It was 2005 when I last wrote an article presenting results of a comparison between Photosynthetically Active Radiation (PAR) meters, and the lamps used during testing were metal halides of various kelvin ratings (see Riddle, 2007). In those days, the use of light-emitting diodes (LEDs) for aquaria was something discussed by only a few. Nowadays, use of metal halide lamps is much less popular and usually seen over larger aquaria or those of die-hard fans, yet, to my knowledge, there have been no updates on the utility of different brand PAR meters and their responses when judging output of LEDs.

This article will compare the responses of three quantum meters when measuring LED light output. Specifically, these are meters manufactured by Apogee Instruments™ (model QMSW-SS; Logan, Utah), Li-Cor Biosciences™ (LI-1400 datalogger and LI-189 sensor; Lincoln, Nebraska) and Spectrum Technologies™ (FieldScout; Plainfield, Illinois).

Product Details

Li-Cor LI-1400 Quantum Meter and LI-189 Sensor Li-Cor Biosciences (Lincoln, Nebraska, USA) is noted for quality instruments, and their meter/sensor combinations have gained wide acceptance within the scientific community. Quality comes at a price (the referenced combination currently costs more than $3,000). The sensor construction is an intricate one - see Figure 1. In addition, the sensor is relatively large and the cord exits the bottom. These facts restrict its use to larger aquaria.

Figure 1. Typical construction of an expensive PAR sensor, such as Li-Cor's. From Kirk, 2000.

Apogee Quantum Meter Apogee Instruments (Logan, Utah, USA) manufactures entry-level PAR meters and sensors, and many hobbyists have found favor with them due to their affordability. The sensor is relatively small and its cord exits the side making it ideal for use in tight quarters (such as aquaria).

FieldScout Quantum Meter Spectrum Technologies (Plainfield, Illinois, USA) manufacturers a number of products aimed at the agricultural/horticultural markets. Although the meter tested here is the FieldScout Light Meter, the sensors are interchangeable with other Spectrum products (such as their wonderful WatchDog datalogger). The sensor tested here was custom-built for my lab for use when testing artificial light sources. Spectrum does not recommend their quantum sensor for use with LEDs but I wondered just how much of an error there actually is, hence I have included it in this review.

In all fairness, we're comparing an expensive instrument (the Li-Cor setup costing over $3,000) to relatively inexpensive ($300-$400 or so) units. A calibrated light source would be needed to accurately judge the responses of all three meters. This luxury was not available for this review, hence the Li-Cor meter - based on the advertised responses of all three meters - will be considered 'correct'.

There are several things that can affect a quantum meter's reading, these include:

• Spectral sensitivity of the sensor
• Spectral quality of the light
• Sensor Cosine Correction
• Sensor Construction (2 pi or 4 pi)
• Testing medium (air, water, etc.)
• Condition of the sensor (physical damage, age - 'fogging' of optical components, cleanliness)
• Sensor/meter calibration
• Temperature
• Light source used for calibration by the manufacturer

These terms will be used throughout this article:

Glossary Actinity Error: A perfect PAR sensor would be equally responsive to all wavelengths of light between 400nm and 700nm. In practice, this is not possible and response difference between a real sensor and a theoretical one is called the actinity error. Various sensors over- or under-report blue wavelengths while red wavelengths are often under-reported.

Correlated Color Temperature (CCT): is a specification of the color appearance of the light emitted by a lamp relating its color to the color of light from a reference source (a blackbody) when heated to a particular temperature, measured in degrees Kelvin (K). The CCT rating for a lamp is a general "warmth" or "coolness" measure of its appearance. However, opposite to the temperature scale, lamps with a CCT rating below 3,200 K are usually considered "warm" sources, while those with a CCT above 4,000 K are usually considered "cool" in appearance.

Cosine Correction: A light sensor should be able to accurately measure light at angles to ~90 of normal incidence (0), and a cosine-corrector allows this. Two cosine-correction types exist - one type is a hemispherical plastic diffuser dome (used by Apogee and Spectrum Technologies), while the other is a plastic cylinder (that should rise slightly above its housing in order to properly collect light, which the Li-Cor sensor does).

All sensors are advertised to be cosine-corrected, meaning their response will be the same to a beam of light, regardless of that beam's angle of incidence to the sensor (up to a point. Li-Cor advertises their sensor to be correct for light falling at an 80 angle from normal while Apogee states their sensor is ±1% at a 45 angle (from zenith) and ±5% at a 75 degree angle from zenith).

Full Width Half Maximum (FWHM): This is an important concept in light measurement. It is simple and easily defined. While the spectral width of the light source could extend for some distance, the maximum is easily determined as is the half-maximum. FWHM is generally used to define peaks and half-maxima of relatively narrow bandwidths (such as LEDs and other 'specialty' cases such as fluorescence). See Figure 2.

Figure 2. Full Width Half Maximum (FWHM) is an important concept, especially with narrow bandwidth light sources such as LEDs. In this case, the peak is at 500nm with a FWHM of ~50nm (475-525nm).

FWHM is not used for broadband light sources (such as sunlight and most artificial light sources). Let's take an example of why FWHM is important. See Figure 14 - it is the spectral characteristics of a combination of blue and white LEDs. This example would share the FWHM characteristics of a blue LED while ignoring the full spectrum characteristics.

Immersion Effect: Reflection of light within a sensor immersed in water is less (relative to a measurement made in air) and results in a greater loss of light. This is due to the refractive indices of plastic and air or water. Hence, more expensive devices (such as the Li-Cor) allow for an 'air' or 'water' calibration to overcome the immersion effect. The Apogee and Spectrum Technologies meters do not offer this option.

Integrating Sphere: A device used in measuring light and especially useful when determining flux or spectra of LEDs. Basically, it is a hollow sphere with a diffusive interior coating. Two ports (one for the LED and the other for a light sensor) are at a 90 angle to one another.

Lambertian Reflectance: Diffuse reflectance is that which appears to be of the same brightness regardless of the observer's viewing angle. Labsphere's Spectralon (a fluoropolymer) offers an almost ideal Lambertian surface. Barium sulfate is a less expensive - but less Lambertian - material.

Light-emitting Diode (LED): A light emitting device consisting of a positive/negative junction where a small amount of electrical current excites metallic compounds doped on a small 'cup'.

Photosynthetically Active Radiation (PAR): Light energy powers photosynthesis. This light's bandwidth has been standardized to that electromagnetic energy between 400 and 700nm (violet to red) per area unit (often 1 square meter) per time unit (usually 1 second). PAR is reported as Photosynthetic Photon Flux Density (PPFD) in units of micromole photons per square meter per second (µmol·m²·sec).

Reflectance: The ratio of the total amount of radiation, as of light, reflected by a surface to the total amount of radiation incident on the surface.

Two pi Sensor; Four pi Sensor: Sensors that collect light only from the direction the sensor is pointed is called 2 pi. A scalar sensor collects light from all directions. A 4 pi scalar sensor resembles an incandescent light bulb. See Figure 3.

Figure 3. Two types of Li-Cor PAR sensors. A 2-pi sensor is on the left (like the one used in this report). A 4-pi sensor is to the right.

Spectral Responses of Three PAR Sensors

Understanding the spectral sensitivities of different PAR sensors is helpful in understanding how accurate measurements will be, especially when dealing with narrow bandwidth light sources, such as LEDs. For our purposes, there are two types of sensors - silicon and gallium arsenide phosphide (GaAsP). The Li-Cor sensor is the silicon type, while the Apogee and FieldScout sensors appear to be made of gallium arsenide phosphide. Figure 4 shows the spectral sensitivity of the Apogee meter, Figure 5 the FieldScout's, and Figure 6 that of the Li-Cor. Unfortunately, Spectrum Technologies does not provide the relative ideal response of their sensor and we therefore must make some assumptions about the actinity errors. Figure 7 is a side-by-side comparison of the Apogee and Li-Cor responses.

Figure 4. The Apogee quantum sensor underestimates violet/blue and red wavelengths. Apogee advertises their sensor is responsive to light wavelengths in the range of 409nm to 659nm. After Apogee Instruments' website.

Figure 5. Response of the Field Scout Quantum sensor - it appears to be an unfiltered gallium arsenide phosphide (GaAsP)-based photo-sensor. No ideal response information is available. After data on Spectrum Instruments' website.

The Apogee meter apparently uses a gallium arsenide phosphide (GaAsP) based sensor with a lens/filter in order to slightly correct the sensor's response. However, it is generally agreed that this type of sensor underestimates violet/blue light (400-500nm) and red wavelengths above 650nm.

Figure 6. The Li-Cor quantum sensor underestimates violet (410-420nm) slightly, and red light (690-700nm). This sensor's response is the gold standard in botany/phycology research fields. After data on the Li-Cor website.

Figure 7. A comparison of the Apogee and Li-Cor sensors' responses. The Spectrum meter is not included due to little available information on its spectral response in relation to ideal response.

Effects of Temperature

Apogee's calibrates their quantum sensors at 68F (20C). It reads 0.6 percent high at 50F (10C) and 0.8 percent low at 86F (30C) - see Figure 8. Li-Cor states a change of ± 0.15% per °C (maximum).

Figure 8. Effect of temperature on Apogee PAR measurements. Calibration is done at 68F (therefore, 'zero' error). At the temperature of most tropical reef aquaria, the reading would be 0.4-0.5% low.

Relative Humidity

When making sunlight measurements, the amount of water vapor (humidity) in the atmosphere can cause lower than expected readings. See here for details:

http://clearskycalculator.com/model_accuracyPPF.htm#RH

Note that all reported measurements were made in the air and the impact of the ultimate humidity - water - will impact meters' responses.

'Sun' and 'Electric' Measurements

In the models tested here, Apogee and Spectrum meters offer two measurement modes to overcome deficiencies in the spectral responses of their sensors. Testing revealed that, on average, there is a difference of about 10% between the two modes. However, spectral quality decides which mode is best for a given light source.

Our testing begins with:

Response of Meters to Sunlight

Figures 9 and 10 show the meters' responses to broadband light energy (sunlight, during an overcast morning) and the spectral quality of that light, respectively. As we can see, all meters do a reasonable job of reporting PPFD.

Figure 9. A comparison of the Apogee, FieldScout, and Li-Cor sensors' responses to the light field on a cloudy Hawaiian morning. See spectral characteristics in Figure 10. At this intensity, the Apogee reads ~10% high, and the Field Scout reads ~13% when compared to the Li-Cor measurement.

Figure 10. Sunlight spectral quality on a cloudy Hawaiian morning.

Response of Meters to Individual LEDs

As we have seen, each of the PAR meters have done a reasonable job of reporting PAR values of sunlight, even though their sensors' spectral sensitivities vary dramatically. Results of LED testing will now be presented.

Blue LEDs

Blue LEDs are ubiquitous in lighting designed for reef aquaria and are often combined with LEDs emitting 'white' light ('white' LEDs are blue LEDs to which a phosphor has been added. This phosphor absorbs some of the blue light and fluoresces it in a broad spectrum). Two blue LEDs were examined. See Figures 11 and 12 (notice the differences in the FWHM of the two).

Figure 11. This blue LED's output is maximal at 449nm, with a FWHM of ~430-480nm.

Figure 12. Acan Lighting's blue LED spectral quality (peak emission at 454nm; FWHM=443-467nm). Analysis of Corrected Color Temperature (CCT) revealed these LEDs were at least 50,000 K (measurements bounced between 50,000 and , or 'off the scale').

The following Figure (13) shows the PAR measurements of the Acan blue LED.

Figure 13. Not surprisingly, there are significant differences among the reading of the 3 PAR meters. These are not maximum PAR values.

Blue/White LED Combination

This combination of LEDs is perhaps the most popular among reef hobbyists, although the ratio of white to blue varies. Figure 14 shows the spectral characteristics of Acan Lighting's LED luminaire (ratio of 2 cool white to 1 'royal' blue).

Figure 14. Spectral Power distribution of Acan Lighting's combination of white and blue LEDs.

Figure 15. PAR measurements of Acan Lighting's blue/white combination LEDs. These are not maximum PAR values - that was not the goal of the experiment.

White LEDs

When comparing the spectra of blue and white LEDs, it is easy to see the effects of the phosphors added to a blue LED (these phosphors are the same as those used in broad spectrum fluorescent lamps). White LEDs are often used in combination with 'pure' blue LEDs to mimic the blueness of deeper oceanic waters. See Figure 16.

Figure 16. Acan Lighting's white LED spectral quality. Correlated color temperature (CCT) of these LEDs measured 7,300 K which is generally considered to be 'cool white'.

Figure 17. PAR values of Acan Lighting's 7,300 K 'cool white' LEDs. No attempt was made to ascertain maximum PAR levels.

Cyan (or Aqua) LED

Those manufacturers specializing in reef aquaria lighting have recently begun adding variously colored LEDs to their luminaires (interestingly, the first commercially successful LED luminaire, made by PFO Lighting) used green LEDs in addition to blue and white ones). Use of cyan LEDs has a basis when we examined zooxanthellae photo-pigments. Chlorophyll a is sometimes bound with another photo-pigment - peridinin. This complex absorbs light into the green portion of the spectrum and makes it available for photosynthesis. See Figures 18 and 19 for a spectral characteristics and PAR measurements of a cyan LED, respectively.

Figure 18. This aqua (or cyan) LED has a maximum output of 505nm, with a FWHM of ~490-525nm.

Figure 19. PAR values of a cyan LED as collected in a small integrating sphere.

Green LED

Many of the comments made about the cyan LEDs would apply to the green LED examined here. The chlorophyll a/peridinin complex can absorb the light emitted by this LED. See Figures 20 and 21.

Figure 20. This green LED peaks at 517nm, and has a FWHM of ~495-540nm.

Figure 21. Green light (517nm) intensity measured by 3 PAR meters using an integrating sphere.

Yellow LED

Yellow light is only weakly absorbed by zooxanthellae photo-pigments; however, there is some evidence that yellow light plays a part in intensifying the apparent fluorescence of some orange/red coral pigments. See Figures 22 and 23 for results of testing.

Figure 22. Spectral characteristics of the yellow LED with peak output of 595nm and a FWHM of ~587-603nm.

Figure 23. PAR values of a yellow LED with a peak emission of 595nm. Taken within an integrating sphere.

Red LED

Of all the LEDs examined here, those emitting red light are the most controversial. Very little red light is found at depth on natural reefs and it would seem that use of white LEDs (emitting some red light) would satisfy the visual requirements of the hobbyist while supplying more than enough red for photosynthesis. See Riddle, 2003 for effects of too much red light. I'm presently working on the assumption that if a lot of red light is harmful to zooxanthellae, then a lesser amount is proportionally harmful. I am just beginning a project to investigate red light's impact. This will be a part of my presentation at the 2103 MACNA in Florida (www.masna.org).

See Figures 24 and 25.

Figure 24. This red LED peaks at 647nm (FWHM = ~640-655nm).

Figure 25. Comparative measurements of a red LED within an integrating sphere.

This completes our observations and analyses of PAR meters and LEDs. Now for our conclusions.

Conclusion and Recommendation

I decided to write this article after hearing anecdotal comments such as 'PAR meters are useless for measuring LED output' and 'Corals don't survive long-term under LEDs'. The latter has not been my experience, but I really had no idea about the former statement. The concept for this article seemed valid enough and I suspected the article could be written in short order. I had the meters and the LEDs and making the measurements could be made quickly - or so I thought. After writing almost 300 articles for hobbyist-related publications over the course of over 25 years, one might think I would have a good handle on the complexity of a project. In this case, I thought I could research and write the article in 2 or 3 weeks. As it turned out, this work required months of research, construction, measurement, and analyses. The results are complex. To reiterate, we're comparing two relatively inexpensive meters against one costing roughly 10x as much. When measuring sunlight, the Apogee and Spectrum Technologies meters report PAR values that compare favorably to those of the Li-Cor. Additionally, Spectrum Technologies states on their website that their sensor is not useful in making measurements of LEDs (a bit of an overstatement as we shall see).

This product evaluation took on added complexity when we consider two of the meters offer two measurement modes - in essence, we are comparing 5 meters, not three. The Apogee and Field Scout meters offer the option of two measuring modes ('Sun' and 'Electric'). This is done in order to offset limitations of the spectral sensitivity of their sensors. The more expensive Li-Cor sensor and meter has no reason to offer this option due to the superior spectral response.

Interestingly, the difference in 'Sun' and 'Electric' measurement modes is almost always about 10% (suggesting the difference is simply the result of a preset electronic correction). However, this correction cannot overcome the ability of the sensor to 'see' light. Therefore, Table 1 is offered for those wanting to measure narrow bandwidth light sources such as LEDs.

¹ The impact of volcanic smoke (vog) on the meters' performance is unknown. Although the measurements were made when conditions were considered to be 'mostly sunny', there is a certain haziness to the sky. Vog is known to absorb some ultraviolet radiation. In addition, there is a considerable amount of seawater aerosols in the air.

Simply using the manufacturer's sensor spectra response chart can lead to incorrect conclusions. There were some surprises. It seems to be current wisdom that the Apogee meter under-reports blue light, yet the results of testing showed the meter performed well when in 'sun' measurement mode (while the electric mode read low). Similarly, the Apogee did very well in 'sun' mode when analyzing the output of 7,300 K white LEDs. In addition, the Apogee and FieldScout meters repeatedly performed best when measuring sunlight when in the 'electric' setting.

Based on these observations, inexpensive PAR meter have some utility for measuring light produced by LEDs.

Lux to PAR Conversion Factors

If you have a lux meter, it is possible to convert lux measurements to PAR values. Use these results with some caution - in most cases it would be safe to assume the results will be low.

• Divide blue (450nm) LED Lux by 69
• Divide white (7,300 K) LED Lux by 45
• Divide blue (450nm)/white (7,300 K) combination LED (2:1 white/blue ratio) Lux by 67

Technical Notes

Spectral analyses were performed by Ocean Optics USB2000™ fiber optic spectrometer and SpectraSuite™ software (Ocean Optics, Dunedin, Florida). It took some doing to design and build a workable integrating sphere from scratch (on the order of weeks). Original prototypes were made of papier mâché and were large (6-inch, or ~150mm) diameter, then reduced to 3-inch (76mm). These proved to be too large and did not sufficiently concentrate light. Ultimately, ping pong (table tennis) balls were used. Their exterior were painted white and the interior of the hollow spheres were painted matte white and then coated with barium sulfate (ACS grade) in order to create a surface with good diffuse spectral reflectance characteristics. Barium sulfate was mixed with un-tinted white latex paint (90:10 weight: weight). Two 1/2" (12mm) holes were drilled into the sphere at a 90 angle. An interior baffle was placed adjacent to the sensor port to prevent light from falling directly upon it.

Barium sulfate is known to offer good reflectance at ~425 - 700nm. To check this, the barium coating was compared to a diffuse reflectance standard (Labsphere Spectralon WS-1-SL, a fluoropolymer offering a highly Lambertian surface with reflectivity of 99% at 400-1,500nm). See Figure 26 for the reflectance of the barium sulfate coating.

Figure 26. Reflectance of the integrating sphere's barium sulfate coating. Reflectance is very good for those spectral sources examined in this article. Ideally, the line should be horizontally flat. This figure shows that violet/blue light is reflected a little less well than other wavelengths.

Figure 27 shows the integrating sphere.

Figure 27. The 'table tennis ball' integrating sphere. Light from the LED enters from the right (a slight red glow of a red LED can be seen). Light is reflected by the internal barium sulfate surface and is collected at a 90 angle by a PAR sensor (in this case, one manufactured by Li-Cor Biosciences).

The integrating sphere would not collect enough light in some cases. To overcome this problem, measurements were made of the high intensity output of a LED luminaire manufactured for aquarium use (Acan Lighting, model 600-18B, Commack, NY). See Figure 28.

Figure 28. Acan Lighting's LED luminaire. A sturdy unit - with no fans that can fail!

Determination of Correlated Color Temperature (CCT) was determined with an Ocean Optics USB 2000 spectrometer and SpectraSuite software. In order to do so, the spectrometer's measurements must be calibrated to a known source. To this end, an Ocean Optics' LS-1-Cal tungsten halogen NIST-traceable light source was used. This light source had little use on it and total hours fell well below the cutoff of 50 hours (when re-calibration is required). Settings of the software included a setting for 'emissive' color (that emitted by a light source such as a LED) and 2 Observer (photopic, daylight observer).

Lux measurements were made using a Gossen Luna Pro lux meter (Gossen Foto-und Lichtmesstechnik GmbH, Nürnberg, Germany).

Calibration

Apogee recommends calibration of their meters ever 3 years, while Li-Cor recommends every 2 years. The Apogee meter has not been calibrated since purchase. The Li-Cor LI-1400 data logger is new and its sensor was rebuilt about 5 years ago.

To check if your PAR meter needs re-calibration, see this site:

http://clearskycalculator.com/longitudeTZ.htm

Note: This calculator works if the sky is truly clear. It did not perform well here in Hawaii due to the amount of 'vog' from the continuing volcanic eruption.

References

1. Kirk, J.T.O., 2000. Light and Photosynthesis in Aquatic Ecosystems. Cambridge University Press, Cambridge, United Kingdom. 509pp.
2. Riddle, D., 2005. Product Review: A Comparison of Two Quantum Meters- Li-Cor v. Apogee. http://www.advancedaquarist.com/2005/7/review
3. Riddle, D., 2003. Effects of narrow bandwidth light sources on coral host and zooxanthellae pigments. http://www.advancedaquarist.com/2003/11/aafeature

Many hobbyists dream of tropical locations in far distant places. They often want to recreate that sense of beauty with their aquariums. However, what they often fail to realize is that tropical beauty and thriving reef systems may not be all that far from home. The Tropical West Atlantic is filled with beautiful sea creatures and an Atlantic Biotope can make for a stunning home aquarium. These aquariums are often referred to as Atlantic Tanks or Caribbean Biotopes.

The Tropical Western Atlantic

The Tropical Western Atlantic is a region that encompasses the waters from Northern Brazil, up through the lesser and greater Antilles, the gulf of Mexico, the Florida Keys, Florida, and up towards the Georgia Carolina coastlines. The corals in these areas are beautiful, the fish are stunning, and for hobbyists in the US they are right here in our backyards. Not all animals are found in all areas of the Tropical Western Atlantic, but those common to the US shores are readily available to the hobby. This large area of natural reef habitat is often overlooked and underappreciated in the hobby.

Atlantic Corals

One of the most unfortunate aspects of keeping Atlantic systems is the governmental restrictions on corals. Stony corals (from the Scleractinia) are very rare in the hobby, because they can not be collected for the aquarium trade. These corals are amazing animals creating huge amounts (as in hundreds of square miles) of reef structure throughout the area. In addition, many other "corals" are frequently harvested and serve as great animals for the home aquarium. All sorts of mushroom anemones (Ricordea species) and Gorgonia and zoanthids are very common in the Atlantic. They all make fantastic inhabitants for captive systems and are truly an overlooked addition to a reef aquarium. Atlantic aquascapes are often usually very colorful, full of movement, and unique in their rare appearance in the hobby.

Some of the stationary invertebrates available in the hobby make wonderful inhabitants for home aquaria. The design, health, and structure of the home aquascape is created by using stationary invertebrates. In addition to the corals, these animals are the living structure for reef habitats.

• Mushroom Corallimorphs
• Hydroids
• Zoanthids
• Bryozoan
• Anemones
• Sponge
• Feather Worms
• Barnacles
• Scallops and Clams
• Tunicates

Popularity In the Hobby, from color → size → groups

Historically the popular fishes of the Atlantic were those with lots of color. The motto for collectors was "color sells" as they tried to collect the most colorful of the fish in the waters. That has shifted during the last few years with the rise in popularity of nano aquariums. Currently, small diminutive fishes are the popular choices for livestock. Even the most colorful of the angelfish are no longer in high demand. Small blennies and gobies are now the aim for collectors. Recent trends and advanced hobbyists may be shifting that trend again, with a growing demand for pairs of fishes, harems, schools, and unique specimens.

Atlantic Fishes

This is one area where abundance, variety, color, size, and everything else is at your fingertips. The Atlantic fishes are bold, beautiful, interesting, and often times serve as the highlight in a reef aquarium. What is even more amazing is that they are readily available to home hobbyists. Many local pet stores are unaware of the great market that exists for Atlantic fish, they may also be unfamiliar with what fish are available, and they don't regularly carry these fish. This is all very unfortunate given the gems that are available. Lucky for home hobbyists, some collectors actually sell directly to the public! This means you can get fish shipped straight to your house without a middle man cost, and limited acclimation steps. Places like www.Sealifeinc.net even quarantine the fish and offer medicated treatments before selling a fish. This practice can be a life saver (literally) for your inhabitants.

The Tropical Western Atlantic may not have the diversity and great numbers of fishes found in other areas, but it certainly does have some strikingly beautiful fishes.

10 of the Most Beautiful Caribbean Fishes:

1. Harlequin Pipefish
2. Juvenile Porkfish
3. Redband Parrotfish
4. French Angel
5. Sunshine Chromis
6. Princess Parrotfish
7. Royal Gramma
8. Queen Angelfish
9. Juvenile Stegastes Damsels (longfin damsel, beaugregory damsel, dusky damsel)
10. Color Changing Wrasse (yellowhea wrasse, yellowcheak wrasse, clown wrasse)

Aquarium Setup

A Tropical Atlantic Biotope is set up the same way as any other reef aquarium. The basic principles of water flow, filtration, lighting, and aquascaping all apply. Common base rock is often used in reef tanks, and Eco-friendly cultured rock is also available from Atlantic suppliers. Fields of terrestrial rock have been places in the ocean and have been allowed to grow and inhabit fauna for several years. Companies like Sea Life Incorporated are licensed to grow this rock, harvest it, and use it to preserve surrounding coral reefs. Filter feeding corals that are photosynthetic are also easily purchased and make for stunning displays. If you prefer highly colored and textured corals the ricordea and zoanthids of the Atlantic can not be beat. And if you are into corals that grow fast and provide visual appeal with a gentle saw in the current, then the gorgonian are your choice. Add them together, and you have a rather interesting aquarium.

The challenges of setting up an Atlantic tank do not reside in the reefscape and husbandry. Instead, like most aquaria the challenge is in finding suitable tank mates and understanding their requirements. Selecting livestock choices prior to setting up the aquarium can save you a lot of troubles down the road. Here are some specifics on some common and not so common Atlantic inhabitants.

Common Atlantic Fishes

Butterflyfishes are beautiful, colorful, and abundant in the Caribbean. However, most of them are not reef safe, do not do well on prepared foods, and have a very poor survival rate in the hobby. These fish in general are best left for advanced hobbyists and those looking to study their captive care.

Angelfishes are beautiful, colorful and abundant in the Caribbean. Unlike many of the butterflyfishes these fish readily take prepared foods, often live for several years in captivity, and are all around great choices for the home aquarium. Some angels (especially the larger specimens) have been known to pick on tube worms, small polyps, and some corals. However, they are also easily trained to eat prepared foods and often do very well in reef aquariums.

Damselfishes of these waters are brilliantly colored, hardy, easy to feed, and serve as your typical damsel fish. Unfortunately this also means that many of them grow up to be bland, aggressive, and rather pugnacious. Great beginner fish for many hobbyists as well as some beautiful potential candidates for the nano reef aquarium.

Wrasses of the Caribbean are fantastic! These fish often do well in captivity, are frequently found in very large numbers, are often times very reef safe in captive settings, have wonderful color and personality, and are quite hard. Numerous of species are available that all make stunning additions as showpiece fish in the home aquarium.

Some fishes that are popular in aquariums are found and collected in the Caribbean waters. Hobbyists are often surprised to find out that these common aquarium fish are from the Atlantic.

10 Common Atlantic Fishes in the Aquarium Trade:

• Yellowheaded Jawfish
• Cleaner Goby
• Dwarf Seahorse
• Rock Beauty Angel
• French Angel
• Blue Tang
• Blue Chromis
• Chalk Bass
• Royal Gramma
• Queen Angelfish

Some fish would make great showpieces in home aquariums. They are incredibly interesting and can be perfect specimens for advancing the hobby and knowledge base. Aquarists looking to go beyond simply keeping fish, but really taking on an advanced topic may want to consider these fish.

10 of the Most Intriguing Atlantic Fishes:

1. Flying Gurnard
2. Scorpionfish
3. Trumpetfish
4. Filefish
5. Walking Batfish
6. Flounder
7. Harem of Wrasse
8. Grunts (group)
9. Glassy Sweeper (group)
10. Needlefish

Uncommon Atlantic Fishes

The Silverbody fishes is a general term used to describe a wide variety of fish families. These include the small fishes often found in schools, all the way up to large solitary fishes. Historically unpopular and virtually absent from the hobby the needlefishes, ballyhoos, jacks, mojarras and more are peaking the interest of advanced hobbyists. These fish all offer great potential for stunning displays, a chance to provide new information for the hobby, and unique aquatic systems. For hobbyist looking to stand out from the rest, these silverbody fishes are sure to do just that.

While not popular in the past, some of the Caribbean fishes are now making their way into the hobby. They are often overlooked, but with a growing trend in nano aquariums these fishes may be perfect for your captive care.

10 of the best Caribbean Fishes for the Nano Aquarium:

1. Grunts
2. Damsels
3. Reef Bass
4. Cardinalfish
5. Gobies
6. Blennies
7. Jawfish
8. Clingfish
9. Scorpionfish
10. Hawkfish

Ecofriendly Fish

These Lionfish are part of the ever growing population of lionfish that have colonized the Atlantic waters. These fish are not native to the Atlantic and their removal is an ongoing and never ending process. Collection and removal of these fish is completely Eco-Friendly and hobbyists who purchase them are doing their part to protect the Atlantic waters.

Atlantic Invertebrates

The Atlantic Ocean (tropical areas alone) offer a very large and wonderful selection of invertebrates. The sessile reef invertebrates like Gorgonia, Zoanthids, Anemones and more provide the reef habitat that makes the area so beautiful and full of life. Add to that wide array of mobile invertebrates such as cleaning shrimp, rock crabs, nudibranchs, urchins, sea stars, and sand worms, and you find yourself with a thriving ecosystem. All of these animals play an important role in the reef, and all of them are important in the home aquarium. Beginning hobbyists often overlook mobile invertebrates and focus on the big colorful fishes. However, with time hobbyists learn to appreciate the little forms of life that make an aquarium a living reef structure. These animals are fascinating and their interactions within a community create a complex reef habitat.

Some of the mobile invertebrates found in the Tropical Atlantic are colorful, unique, fascinating, and well suited for home aquaria. Each of these may make great additions to your aquarium and are worthy of further consideration.

1. Banded Shrimp
2. Ornate Snails
3. Ornamental Flatworms
4. Jellyfish
5. Reef Crabs
6. Anemone Shrimp
7. Mantis Shrimp
8. Horseshoe Crabs
9. Chitons
10. Sea Slugs

Conclusion

Often overlooked and underappreciated, the Atlantic biotopes are amazing aquariums. Sustainable inhabitants are here in our own backyards and ready for hobbyists to create new and interesting aquariums. Much can be learned about these animals from captive systems and hobbyists have a remarkable opportunity in front of them to participate in the process and progress.

The art and science of reefkeeping continues its steady progression with introductions of equipment that we only dreamed about in the hobby's early days. Early on, it was recognized that lighting was critical while water motion received relatively little attention. Since the reef hobby was such a tiny fraction of the aquarium trade, few manufacturers were catering to the needs of reefers so hobbyists were forced to improvise. Serious hobbyists were handcrafting dump buckets and siphon-based Carlson Surge Devices. One dedicated aquarist, Jimmy Chen, modified a Little Giant™ pump by adding a model boat propeller. This ingenious concept would have far-reaching ramifications and eventually revolutionized the way we move water in reef aquaria.

After years of sitting on the sidelines, Marineland finally decided to get into the propeller pump business and now offers Maxi-Jets in three configurations: Propeller Pump, Powerhead, and Utility Pump, all available in a single package marketed under the name of Maxi-Jet Pro. These new designs and configurations call for another in-depth look at their performance. How will the New Maxi-Jets compare against the old?

Marineland Aquarium Products' Maxi-Jet pumps have been around for quite some time. These pumps, with their epoxy-encapsulated motors proved to be highly reliable and became workhorses within the hobby. Recently, their design changed as well as their country of manufacture. The original Maxi-Jets were imported from Italy; they are now made in the Peoples' Republic of China. Although similar in appearance, the new pumps are slightly different and parts are not interchangeable between the new and old designs. The manufacturer promises relatively high performance while offering them at very modest prices. Is this a case of 'you get what you pay for' or are they a true value?

Manufacturers' Specifications

These specifications are current at the time of this writing:

Maxi-Jet Powerheads

• Maxi-Jet 400 Pro Powerhead
  • Advertised Flow (gallons per hour/liters per hour): 110/416
  • Impeller Diameter: ~13/16" (21mm), 6 vanes, tan plastic impeller
  • Discharge Diameter: ~1/2" (12mm)
• Maxi-Jet 600 Pro Powerhead
  • Advertised Flow (gallons per hour/liters per hour): 160/606
  • Impeller Diameter: 1-1/8" (29mm), 6 vanes, red plastic impeller
  • Discharge Diameter: ~1/2" (12mm)
• Maxi-Jet 900 Pro Powerhead
  • Advertised Flow (gallons per hour/liters per hour): 230/871
  • Impeller Diameter: 1" (25mm), 6 vanes, yellow plastic impeller
  • Discharge Diameter: ~1/2" (12mm)
• Maxi-Jet 1200 Pro Power head
  • Advertised Flow (gallons per hour/liters per hour): 295/1,117
  • Impeller Diameter: 1-3/8" (35mm), 6 vanes, purple plastic impeller
  • Discharge Diameter: ~1/2" (12mm)

Maxi-Jet Propeller Pumps

• Maxi-Jet 400 Pro Propeller
  • Advertised Flow (gallons per hour): 500
  • Number of Blades: 2 (gray plastic)
  • Propeller Diameter: 1-1/4" (33mm)
  • Discharge Diameter: 1-11/16" (43mm)
• Maxi-Jet 600 Pro Propeller
  • Advertised Flow (gallons per hour): 750
  • Number of Blades: 2 (white plastic)
  • Propeller Diameter: 1-3/8" (43mm)
  • Discharge Diameter: 1-11/16" (43mm)
• Maxi-Jet 900 Pro Propeller
  • Advertised Flow (gallons per hour): 1,000
  • Number of Blades: 3 (gray plastic)
  • Propeller Diameter: 1-7/16" (37mm)
  • Discharge Diameter: 1-13/16" (47mm)
• Maxi-Jet 1200 Pro Propeller
  • Advertised Flow (gallons per hour): 1,300
  • Number of Blades: 3 (white plastic)
  • Propeller Diameter: 1-1/2" (39mm)
  • Discharge Diameter: 1-13/16" (47mm)

Flow Rates - Advertised versus Actual

How much water pumps move is often a prime factor when considering a purchase. Tests were performed according to methods listing in Testing Protocols (below). How do these pumps' advertised flow rates stack? See Figures 1, 2, and 3.

Figure 1. The 'new' Maxi-Jet models 400, 600, and 900 powerheads pump more water than advertised. The 1200 pumps almost exactly what the manufacturer claims.

Figure 2. The 'new' models 600, 900, and 1200 Maxi-Jets pump more than the older design.

Figure 3. Advertised flows were exceeded by all models except for the Maxi-Jet 1200.

Flow Attenuation

The weakening (attenuation) of flow over distance is an important, but often overlooked, concern. Simply looking at the number of gallons pumped per hour or discharge velocities fails to tell the whole story. Knowing at what distance the flow drops below a certain point is valuable information when decided how many pumps to use. On a natural coral reef here in Hawaii, flow velocity is normally about 4 inches (0.25 feet) per second, hence we'll use that figure as a cutoff point. As Figure 4 shows, flow velocity drops below 4 inches per second at a distance of about 17-18 inches from the Maxi-Jet 400 pump's discharge.

Figure 4. Flow velocities as a function of distance.

Figure 5 shows us a Maxi-Jet 1200 propeller pump can push water at a velocity of 4 inches per second about 24 inches from the pump's discharge.

Figure 5. Velocity attenuation of the maxi-Jet 1200 propeller pump.

Power Consumption: Powerheads, New & Old, and Prop Pumps

Reefkeeping is not known as a particularly inexpensive hobby. After initial setup and livestock purchases, there are monthly maintenance costs to consider. Power consumption is usually tops the list of routine expenses. See Figures 6 and 7.

Figure 6. See comments on power consumption in the 'Comments' section below.

Figure 7. Power consumption of Maxi-Jet's four models.

Powerhead Power Consumption - Old versus New

The new Maxi-Jet powerheads (made in China) draw more power than the old powerheads (Italian made). See Figure 8.

Figure 8. Power consumption of the new and old Maxi-Jets.

Power consumption is only part of the story. To be objective, efficiency must be estimated. In order to do this, amount of water pumped was divided by watts. See Figure 9.

Figure 9. New and Old Powerhead Efficiencies. The 'old' Maxi-Jet 400 powerhead was not tested.

Mounting Hardware

The Maxi-Jet Pro box comes packed with various pieces for the three different pump configurations. One of these - a mount with suction cups - can be used with all three. When used to mount the pump to the floor of an aquarium, it will work just fine. Using the suction cups on a vertical surface is a different story. It is only a matter of time before the suction cups lose their grip and allow the pump to fall. Another piece included is a hanger with articulated joint called an omni-directional mount. I found the ball-and-socket friction fit to be sloppy and it would not keep the pump in position. There is an inexpensive fix - once the desired position is determined, a drop of Super Glue on the ball-and-socket joint will weld it in place. I would personally prefer that the new joints were as tight as the old ones. Obviously a flexible joint allows a lot of latitude.

Compatible with Sure Grip Magnets

The new Maxi-Jet omni-directional holder design is compatible with Sure Grip magnets. The magnets are expensive relative to the cost of the pump, they're a good investment considering the investment you've got in livestock.

Noise Pump & At Start-Up

Maxi-Jet pumps operate on alternating current (AC) and this presents some engineering challenges for the propeller pumps. The propeller must spin in the proper direction to push flow into the aquarium. This is a problem with alternating current - at start up, the prop may or may not spin in the correct rotation. To overcome this issue, engineers have incorporated a ratchet-like device at the end of the propeller's axial shaft. If the prop turns the wrong way, it pushes itself into this ratchet stop and once movement is arrested, it should start to spin correctly and pushes itself away from the stop device. Simple and usually effective but there is a downside - when the prop engages the stop, it makes a chattering noise until it begins to rotate correctly. This is one of the reasons why propeller pumps operating on alternating current are not recommended for use with wavemakers (there is also the possibility of damage to the prop assembly).

Noise is not much of an issue when the Maxi-Jet is used in the powerhead or utility pump configurations. The impeller can spin in either direction and still push water. Powerheads can be used on wavemakers.

As mentioned, the propeller volute is held on the motor housing by friction fit. There is a chance that vibration will make a low humming noise if the volute is not properly fitted to the housing.

Are New & Old Parts Interchangeable?

No. Parts of the old and new design are not interchangeable. Any post-market propeller modifications will not work with the new design.

Electrical Cord Length

The four pumps examined here have a cord length of 72 inches (~1.83 meters). Although this detail may seem trivial, it is not. Generous cord lengths (as we have here) are a plus when used with larger aquaria or when dealing with distant power outlets. It is especially important in making 'drip loops' to prevent water from migrating to an electrical outlet.

Comments

Likes:

• Price. If you can't afford these pumps, you should consider a hobby other than reefkeeping.
• Flexibility. These pumps can meet many demands - they can run reactors, small skimmers, and can mix smaller batches of artificial seawater, plus move enough water in smaller reef tanks.
• Marineland's advertising claims generally underestimate their products' performances. The 400, 600, and 900 powerhead models exceed advertised pump rate claims and the 1200 almost exactly matches their flow estimate.
• These new models pump more than the older Italian-made units so it is not surprising that these 'new' Maxi-Jets consume more power. The propeller pumps also exceed the amount of water pumped as claimed by the manufacturer.
• These pumps are listed by Underwriter's Laboratories.
• The new 1200 powerhead is more energy efficient than the older (Italian) model.
• Mounting hardware is compatible with at least one post-market magnet (such as Sure Grip).

Dislikes:

• The friction fit of the omni-directional mount is sloppy and does not hold the powerhead/prop pump in position. Although a fix is simple (a drop of Super Glue will fix the mount in place), I'd rather see tighter tolerances to allow on-going latitude in positioning.
• The shroud for the propeller pump must be carefully placed to allow proper alignment with the propeller assembly's axial shaft. There will be vibration if there is a lot of misalignment. I have heard reports of the propeller housing coming loose and 'blowing off'. I didn't see this during testing and feel the friction fit of the housing to the pump motor is enough to hold it in place. It is possible that misalignment and resulting vibration could be to blame for the housing coming off. If misalignment is relatively minor, no vibration is apparent and it's possible that flow output will be reduced. I had problems getting proper alignment on the 1200 and reduced flow was not apparent unless I checked the power draw with a watt meter, or determined flow velocity with an electronic water velocity meter.
• Suction cup mount for vertical surfaces. These invariably become detached.
• The new 600 and 900 model powerheads are less energy efficient than the older model powerheads.
• No foam covers to keep foreign particles from entering the prop pumps are offered.

Recommendations

Based on flow attenuation data presented above, two or more of the propeller pumps should be adequate for smaller reef aquaria (up to ~20 gallons). More should be used for larger tanks. Do not use the propeller pumps with fishes that 'pick' such as Chelmon butterflies (or any of the longnose butterflies) - they whirling motion of the moving prop attracts their attention. Disaster awaits when their snouts meet the propeller.

These pumps are not perfect and the propeller versions suffer from some design issues, however, they perform as advertised or better, and the price makes them attractive to budget-minded hobbyists sensitive to the cost of the pump.

Warranty

Marineland Aquarium Products warranties these pumps for 2 years after date of purchase, and will repair or replace defective parts at their option. See www.marineland.com for details.

Testing Protocol

All pumps were tested in a 240-gallon test tank (8'x2'x2') filled with saltwater at a specific gravity of 1.025. Water velocity was measured with an electronic water velocity meter (FloMate 2000 made by Marsh-McBirney, Frederick, Maryland, USA). Velocity was plugged into this formula (Flow=Velocity x Area) in order to determine flow rate of gallons per hour. Electricity consumption was monitored by a Kill-A-Watt power meter made by P3, International.

I was scheduled to give a presentation to a reef aquarium club some time ago, and I figured I'd try to do something different after the talk. I asked to have everyone coming to the talk bring all of their water testing kits, expired or not, just to see what would happen if a bunch of hobbyists tested the same water samples with different kits. With the help of my colleague and organic chemist Dr. David Flanigan, I got some water samples ready, and the club members brought in 14 pH kits, 9 nitrate kits, 14 calcium kits, and 12 alkalinity kits. They brought in 10 refractometers/floating hydrometers, too.

I gave out some slips of paper that asked for the brand/type, expiration date, result, and any comments, and asked to have them filled out accordingly. I also asked them, time allowing, to give their kit to someone else when they finished with it, so we could see what happened when two people tried using the same kit. So, I'll give more than one result for some kits, but only one for many others.

Note that no one was told where the water samples came from before testing in order to help reduce any bias in findings. In fact, they were told that some of the water wasn't from an aquarium (it wasn't). The results of these tests were quite surprising to say the least, and are certainly worth a look. Make sure that you look at the whole article (for reasons you'll see below).

Refractometers/Hydrometers

To test the refractometers/hydrometers, we used a calibrated MA877 Milwaukee Seawater Digital Refractometer to measure the specific gravity of a few gallons of water from one the aquariums I maintain at school. The specific gravity at 23°C was 1.024.

A Milwaukee MR100ATC refractometer used in this study.

Instant Ocean Hydrometer.

pH Kits

To test pH kits, we used the same water that was taken from an aquarium. David used a triple-calibrated Oakton Instruments Testr-2 digital pH meter and found that the pH of the sample was 8.2.

A typical Salifert pH test kit utilized in this study.

Nitrate Kits

To test nitrate kits, I did not want to use tank water as I expected it to have a very low concentration. So, David made up a standard for us to use, which had a nitrate concentration of 25ppm.

A Red Sea Nitrate Pro test kit.

Calcium Kits

To test calcium kits, we again used the aquarium water. I took a sample and sent it to a local water quality lab and they reported that the concentration of calcium was 338ppm.

API Calcium Test Kit.

Alkalinity Kits

To test alkalinity kits, we used the same aquarium water. And again, I took a sample and sent it to the lab, which reported that the alkalinity was 3.3meq/l. Note that different kits may report results in either ppm, meq/l, or dKh, but I have converted all results to meq/l for ease of comparison.

Seachem MultiTest for pH and Alkalinity.

Comments

First, I'm just the messenger reporting results turned in by a group of reef aquarium hobbyists. So please don't sue/shoot me if you don't like the findings! Other than that, what a mess. The results for many types and brands of kits are obviously all over the place, and I guess the question is why that's the case.

Well, most of the kits were expired, which could obviously cause problems. Although, in some cases the expired kits performed as well as or even better than the current ones. Of course, that could have simply been random chance. So, it would seem that either (many of) the kits are simply inaccurate, or the method of use produces unreliable results, or (many) hobbyists just aren't good at following directions and using the kits properly - or any combination of these.

As far as user error goes, this could occur for many reasons and some kits had easier to follow instructions than others. Likewise, some kits are simply easier to use and/or produce results that are easier to read. And, in the case of one of the hydrometers being a little off on the high side, all it takes is a single tiny bubble stuck on the back-side of the swing arm to give such a result. In other words, there are plenty of opportunities to mess things up. So, I'll take things a step further to show that user error very likely plays a significant role in the apparent poor performances of many of the kits above, especially in cases where a kit was tested twice and gave significantly different results.

Alkalinity Kits - Part II

At a different time I also wanted to see what sorts of results would be produced if the same person took their time and used the same kit, on the same sample, repeatedly. So, David and I used our own kits and our own funds to go out and purchase a few more from a couple of local shops. We only got one of each brand of kit available to us (did I mention it was our own money?), but we figured that even testing one kit of each brand could be very informative. Besides, any of the kits we purchased could have been the kit that the next hobbyist needing one would have bought.

Depending on the type of dye used by the manufacturers of these kits, some can apparently be used equally well for freshwater and saltwater. However, others may give results that vary as much as 10% between the two (Holmes-Farley 2002). I wouldn't consider this to be significant, though. So, we figured we'd do both to see what happens.

David made a freshwater standard in the lab, which had an alkalinity of 3.5meq/l, and also made up a fresh batch of seawater using DI water and a popular salt mix, which was aerated for a few hours afterwards then allowed to sit for several more. This sample was then tested 6 times (3 times by each of us) with a Hach alkalinity kit, which coincidentally and consistently indicated an alkalinity of 3.5meq/l. Note that while we are comparing results of kits with the results of a kit, the point here is to look at consistency of results.

After preparation, each test kit was used 6 times to determine the alkalinity of the freshwater standard and 6 times to determine the alkalinity of the seawater sample. Note that rather than have one person perform all 6 tests on each sample, we decided to do 3 tests each on both samples for two reasons.

First of all, this could shed some light on how two people may do things differently even when following the same set of instructions. For example, when any given set of instructions says "fill to the line" two people may have different ideas of what this means. You've probably seen water form a meniscus when put in a glass container, and one person's idea of filling to a line may mean that the top of the meniscus touches the line, while another may think that the bottom of the meniscus should be at the line, etc.

Secondly, I'm partially colorblind. We thought this might be significant in some cases, as these kits require users to compare a colored liquid (the test medium) to a colored chart or scale of some sort to determine test results. Approximately 8% of males (but only 0.5% of females) are at least partially colorblind (Wikipedia 2012), meaning many hobbyists may have trouble with various colorimetric test kits due to a visual deficiency. So, we both performed the tests to see if I would have any particular difficulties not experienced by David.

Lastly, as noted above, different kits report results in either ppm, meq/l, or dKh, but I have converted all results to meq/l for ease of comparison.

Notes:

Instant Ocean: This kit was not expired, but oddly enough an expiration date could not be found on the outside of the package.

API: This kit had no expiration date indicated.

Note that the instructions said to cap the test vial with the included cap and to shake the sample after each drop added. However, the cap did not fit well and shaking the sample allowed some sample water to escape the test vial. So, while we started with the seawater sample, the remaining tests performed by both of us were done without the cap, by swirling the sample in the vial.

Red Sea: This kit was not expired.

Freshwater notes: We agreed during all six tests that the final color was a little darker than the darkest part of the scale that comes with this kit. The scale stops at 3.6, so the results may have been slightly higher than 3.6.

Saltwater notes: Note that Riddle (2007) tested Red Sea's alkalinity kit using a seawater sample and found the results to be approximately 19% low.

Seachem: This kit had no expiration date indicated.

Riddle (2007) also tested Seachem's alkalinity kit using a seawater sample and found the results to be within about 10% of expected.

Salifert: This kit was not expired.

Riddle (2007) also tested Salifert's alkalinity kit using a seawater sample and found the results to be about 11% high.

Nutrafin: This kit was not expired.

More Comments

Now we see a very different picture. As you can see, consistency was actually surprisingly good for any given test when tested by one of us, although in some cases David and I got somewhat different results for the same kit. For example, when I used the Instant Ocean kit for the seawater sample I got 3.5meq/l all three times, but David got 3.25meq/l all three times. When it comes down to it, I personally find a variance of only 0.25meq/l to be very good for an easily affordable hobbyist test kit. For that matter, all results for all kits on each of the samples were within 0.5meq/l.

So, with all this in mind, here are some suggestions: Always check expiration dates on kits and make sure they are up to date. Don't test when you're in a hurry. Sit down, take your time, and thoroughly read the instructions. I think it would also be a good idea to use any new kit at least three times on a single sample to see if you/the kit can provide consistent results. If you get different answers, try to figure out if it's you doing something a little different each time, or if it's the kit. If you're convinced it's the kit, try a different brand. And, as far as overall accuracy goes, it seems that lately there are more and more kits of various sorts that come with their own standards. These should allow you to check a kit's accuracy yourself.

For the manufacturers of the kits, the instructions on many of these (but certainly not all) were not easy to understand/follow, especially for inexperienced hobbyists. For best results, adding some pictures would likely be very helpful. For example, a picture of what "fill to the line" for a given kit means, etc. would be great and easily clear up any confusion. With respect to alkalinity kits, it would also be nice if everyone would use meq/l.

References

1. Holmes-Farley, R. 2012. Chemistry and the Aquarium: What is Alkalinity?. Advanced Aquarist 1(2). URL: http://www.advancedaquarist.com/2002/2/chemistry.
2. Riddle, D. 2007. Product Review: Alkalinity Test Kit Showdown. Advanced Aquarist 6(8). URL: http://www.advancedaquarist.com/2007/8/review
3. Wikipedia, 2012. Color blindness. URL: http://en.wikipedia.org/wiki/Color_blindness

With the help of my colleague David Flanigan, an organic chemistry professor and fellow reef aquarist, I tested the effectiveness of some reflectors used with T-5 fluorescent bulbs in aquarium lighting fixtures. We knew that any sort of reflector in a fixture would help send more light downward into a tank, but we wanted to see some hard data, and wanted to compare a couple of different types of reflectors in the process. So, we set up a test tank, got a light meter and a couple of fixtures, and got to work.

To start, we cut up and marked some eggcrate, attached it to a PVC frame we built (along with uprights of different lengths that could be switched out to take readings at different depths), and got a light meter. We went with the Apogee Instruments Quantum Meter with a cabled sensor, after reading Riddle (2005 & 2008) and talking to lighting expert Sanjay Joshi. This meter measures PAR (Photosynthetically Active Radiation), the important part of the spectrum for organisms that use light, which is also called PPFD (Photosynthetic Photon Flux Denisty). It does this, and then reports intensity in units called micro-Einsteins per square meter per second (µE·m²·sec) or micro-Mol per square meter per second (µMol·m²·sec). Riddle (2008) covers this in more detail, so give it a read if you like.

There are numerous pre-fabricated T-5 fixtures available, and all that I've seen have some sort of reflector included. However, some fixtures have a single reflector that's typically a flat or curved sheet of polished aluminum mounted above all the bulbs in the fixture, while many others have a single, smaller aluminum reflector for each individual bulb. These tend to wrap around half of the bulb and have some number of bends/folds in the aluminum. So, we got one of each type of fixture and tested both. During our tests, we made some other discoveries, quite on accident, and I want to go over a couple of these first, though.

The Background Effect

While some aquarists might leave the back of their tank alone, or may cover it with a sheet of colored plastic, it's common practice to tape up the sides and top of a new tank and spray paint the back of it blue or black. However, one of the accidental discoveries we made was that this can significantly reduce the amount of light that is reflected into a tank.

Our test tank was a 95 gallon tank with dimensions of 24" high x 18" wide x 48" long, as this is a popular footprint, and we did much of our testing with the tank full of water after we found that this can also make a significant difference in readings. The tank was also painted light blue on the backside.

Like those of many hobbyists, our test tank had a painted blue background.

When we started testing, we assumed that light readings would always be lower at the front of the tank and higher at the back. The reasoning was that some of the light from the bulbs should be reflected off the front pane of glass back into the tank and off the rear pane of glass into the tank - but that more light would "escape" through the clear front pane, while more would be reflected back in from the painted back pane. However, were wrong, as the readings at the front of the tank, without exception, were higher instead of lower than those at the back of the tank.

To develop an understanding of why this happened, look at the lighting "footprint" below of our TX5 48" fixture that houses five 48" T-5 bulbs, which was generously donated by Aquactinics. The units are PAR (as µMol·m²·sec) measured in the tank with the sensor at 10" water depth, and note that the front of the tank is at the bottom of the figure. Average PAR at the front of the tank was calculated by adding the 11 readings taken at approximately 1" from the front pane of glass during each test and dividing that sum by the number of readings taken (11).

Notice that the light intensity was lower at the back of the tank where the average was 167 µMol·m²·sec (top of the footprint), and higher at the front where the average was 234 µMol·m²·sec (bottom of the footprint). We found that the same thing happened when we later tested our Nova Extreme fixture that houses four 48" T-5 bulbs, our Orbit fixture that houses four 21" PowerCompact bulbs, and even our Outer Orbit fixture that houses four 48" T-5 bulbs and two 150w DE metal halide bulbs (all of which were generously donated by Current USA). For some reason the painted blue background, without exception, made the back of the tank darker than the front.

It occurred to us that we could take a look at the effect a colored plastic background would have on readings. So, we tightly taped a blue plastic background to the front of the tank to see if the readings would then equal those at the back. The background material we had was about the same color blue as the paint on the back of the tank, so we thought that's what would happen. Wrong again. Let's look at the new footprint, again with the TX5 fixture and everything else the same except for the addition of the plastic sheet.

Well, it looks the same. The readings were essentially the same as before, being ever so slightly higher at the front of the tank. Apparently it was something about the paint itself, rather having something blue on the front/back of the tank. So, just for the fun of it we tried a black plastic background. It didn't really change the readings, either. Thus, it seemed that the color of the plastic sheer didn't matter. The front was still brighter than the back.

Then Dave had a great idea. Next, we tried the blue plastic background again, but this time we wetted the glass on the front of the tank, stuck the plastic to it and then pushed all the air bubbles out from underneath it. Basically our simulated painted background looked just like the real painted background, and was stuck onto the pane itself with no air in between the plastic and the glass. This time we got something totally different, as you can see on the new footprint.

Oddly enough, the readings at the front mirrored those of the back of the tank. Note that the average PAR at the front of the tank is approximately 30% lower than it was when we started, and is essentially identical to the readings along the back (an average of 166.6 µMol·m²·sec for the back vs. 166.9 µMol·m²·sec for the front)!

Okay, so we did one more. Next, we wetted the front of the tank and did the same thing with the black plastic background. The readings dropped even lower, as the average at the front was 155 µMol·m²·sec. So, the front of the tank, with its simulated painted black background, was noticeably darker than the back of the tank with its painted blue background. In fact, the average PAR was down approximately 34%.

Again, this was not what we expected at all. So, we tracked down physics professor Brain Lane, looking for a possible explanation. As he explained, in simple terms, when light leaves its source and hits the panes of glass in the tank, some of that light escapes through the glass, but some is reflected off the inner surface of the glass and heads back into the tank. As strange as it might sound, some of the light also reflects off the inner "surface" of the outer side of the glass pane, too (see the figure below). However, apparently having something "sealed" against the glass, such as blue paint or a wetted blue plastic background stops some of the light from reflecting off the inner surface of the outer side of the glass pane. If anything else was going on, taping the dry plastic background on the tank would have the same effect - but it didn't.

Some light bounces off the inner surface of the glass back into a tank, and some also bounces off the inner surface of the outer side of the glass pane.

Yes, that sounds odd, but you can easily see some of the weird reflections created when mixing glass, air, and water. Have you ever noticed that if you look right through the front of the tank it looks clear, but if you look through the end of your tank the front pane of glass looks like a mirror? Take a look now if you've never noticed this before. Of course, this doesn't happen if there's no water in the tank, as you can see right through the front pane, even when looking at it through the end of the tank.

Anyway, at this point I want to make some basic recommendations related to the topic. 1) If you have a wall of live rock from the bottom almost to the top of your tank, then don't worry about the background too much. Most of the reflection takes place several inches from the top of the tank. 2) If you have considerable areas of glass exposed at the back of the tank, unobstructed by rocks, use a taped on plastic background instead of paint. Or, try putting your tank close to a wall and just paint the wall behind it blue/black. Again, this can result in the back of the tank being as much as 30% brighter than if it was painted. 3) Always keep your glass clean to promote better reflection regardless of backgrounds, which includes scraping away coralline algae. 4) Don't paint the front of your tank :)

For a different look, I put nothing on the back of this 55 gallon tank and just painted the wall behind it blue.

The Temperature Effect

In addition to the background effect, we also noticed another pattern in the numbers that persisted regardless of the type of fixture. The readings were always lower at one end of any given fixture than at the other end, and if you scroll back up and look at the footprints above, you'll see this. The readings were always a little higher on the left end of the TX5 fixture, and we found that this caused by a difference in bulb temperature from one end to the other.

I'll go into more detail on this in a future article, but for now it's enough to point out that the 3" exhaust fan in the fixture was on the right end and it drew relatively cool air from the room into the left end. As the air passed over the bulbs it became increasingly hotter, meaning the bulbs were slightly cooler at the left end of the fixture. Every bulb has an optimal operating temperature, and in this case the bulbs' output fell off a little at the right end of the fixture due to the increase in temperature.

While the end to end differences weren't drastic by any means, they were consistently there. It's unlikely that anyone will be cutting holes in a pre-fabricated fixture and/or upgrading the included fans, but if you decide to install a lighting retro-fit kit into a canopy, be sure to use an appropriately-sized fan(s) for the job and give some thought to placing it/them in the top-center of the canopy with vents in both ends. Putting the fan in the top-center and vents in the ends would decrease the distance that room-temperature air travels over the bulbs, and would keep both ends of the bulbs at approximately the same temperature.

Test Results for a Fixture with a Single Reflector

Okay, let's get on to how we tested some T-5 bulbs with a single sheet-type reflector that has a single fold down each edge, and what we found. To start, we grabbed our Nova Extreme fixture that houses four 48" T-5 bulbs and includes a single polished aluminum sheet mounted above bulbs. Then, we covered the entire reflector with black electrical tape. We put the bulbs in, set the fixture up over our testing rack, and fired it up. One little thing to note here is that we waited about half an hour to start taking readings, as we found that it takes a while for systems to warm up and the light output to stabilize. Again, output changes depending on bulb temperature.

After everything was ready, we took a series of readings to measure PAR using our meter. Readings were taken at fifteen positions under the fixture, five from end to end and three across (see the grid on the figures below). Note that the bottom of the fixture was approximately 5.25" inches from the top of the light meter's sensor.

After finishing that up, we pulled out the black tape, got the fixture warmed up again, and took the same series of readings. This let us make a direct comparison between the light that would be going down into a tank with and without the reflector.

With the reflector blacked-out the highest PAR reading we got was 191 µMol·m²·sec. We also found that the average PAR was 155 µMol·m²·sec, which was calculated by adding all the readings together and dividing the sum by 15. With the tape pulled off the reflector the highest PAR reading was 435 µMol·m²·sec, and the average PAR was 342 µMol·m²·sec. That's quite a difference to say the least, as the average PAR went from 155 to 342 µMol·m²·sec! So, it should be quite clear that the use of a sheet-type reflector can make a heck of a difference in the amount of light going from a T-5 bulb to the critters in your tank.

Test Results for a Fixture with Individual Reflectors

Next, we tested our TX5 48" fixture that houses five 48" T-5 bulbs with individual reflectors for each bulb. They're the type that has numerous folds, and have a little ridge that runs right down the middle of the reflector, too. This little ridge is supposed to angle away the light going straight up from the bulb, rather than reflecting it straight back down into the bulb. Again, these reflectors wrap around each bulb to some degree, and we expected them to be even better than the single sheet-type reflector. Note that due to the width of the fixture we decided to use only three bulbs in it, so the readings we got were lower than those presented above. This doesn't really matter though, as we were looking for the change in readings with and without reflectors rather than the total output of a given fixture.

Again, we covered each of the reflectors with black electrical tape, put the bulbs in afterwards, set the fixture up over our testing rack, and warmed it up. We took a series of readings in the same manner, and then pulled out the black tape, got the fixture warmed up again, and took the same series of readings once again.

With the reflectors blacked-out the highest PAR reading was 128 µMol·m²·sec, and the average PAR was 101 µMol·m²·sec, which again was calculated by adding all the readings together and dividing the sum by 15. With the tape removed the highest PAR reading was 451 µMol·m²·sec, and the average PAR was 304 µMol·m²·sec. So, we were right to think these would send even more light downwards, as the average PAR went from 101 to 304 µMol·m²·sec! Thus, again, it should be obvious that the use of well-designed reflectors, individual-types in this case, can make a huge difference in the amount of light going from a T-5 bulb down into a tank.

Other Bulbs

So, what about V.H.O. bulbs? Do reflectors make as big a difference? Well, all of the V.H.O. bulbs I've ever used had an internal reflector. I assume that's because they have a larger diameter making it easier to add some sort of coating to half of the inside of the bulb to send all the light in one direction. However, we didn't do any sorts of tests on V.H.O.s and I've never broken one open to see what's in there, so I'm not positive about that. Regardless, I don't know of anyone that makes individual reflectors for V.H.O. bulbs. Maybe we'll try a sheet-type reflector with some in the future though, just to see if there's any difference. Likewise, the bulbs used in the L.E.D. fixtures I've seen always come mounted in little individual reflectors, so we didn't test any L.E.D.s without reflectors, either.

Metal halide bulbs and the reflectors made for them come in a range of shapes and sizes and finishes, but there's already a good bit of information about these available. Sanjay Joshi has looked at many of them and written up the results in a series of articles (see references below), but what I'll tell you here is that the right reflector can make a huge difference, and the wrong one won't help much. So, if you're thinking about retro-fitting some into a canopy, I recommend you do some homework on bulb/reflector combinations.

Bottom Line

It is imperative that you use reflectors with T-5 bulbs, and individual reflectors do a better job of sending light into a tank than a single reflector. If for some reason you decided to add some T-5s to a canopy yourself, the data show that you'd need three bulbs without reflectors to send the same amount of light into the tank as one bulb with a quality individual reflector! Also, don't paint the back of your tank, and make sure that your bulbs are adequately cooled for optimal performance.

References / Sources for More Information

1. Joshi, S. and Marks, T. 2003. Analyzing Reflectors: Part I - Mogul Reflectors. Advanced Aquarist's Online Magazine: 2(3).
2. Joshi, S. and Marks, T. 2003. Analyzing Reflectors: Part II - Double Ended Lamp Reflectors. Advanced Aquarist's Online Magazine: 2(7).
3. Joshi, S. and Marks, T. 2004. Analyzing Reflectors: Part III. Advanced Aquarist's Online Magazine: 3(3).
4. Joshi, S. and Marks, T. 2004. Analyzing Reflectors: 400w DE Reflectors. Advanced Aquarist's Online Magazine: 3(12).
5. Joshi, S. and Marks, T. 2006. Analyzing Reflectors: Part V. Advanced Aquarist's Online Magazine: 5(2).
6. Joshi, S. 2006. Facts of Light Part I: What is Light? Reefkeeping: 5(1).
7. Joshi, S. 2006. Facts of Light Part II: Photons. Reefkeeping: 5(2).
8. Joshi, S. 2006. Facts of Light Part III: Making Sense of Light Measures. Reefkeeping: 5(3).
9. Riddle, D. 2005. Product Review: A Comparison of Two Quantum Meters - Li-Cor v. Apogee. Advanced Aquarist's Online Magazine: 4(7).
10. Riddle, D. 2008. Product Review: Lighting for Reef Aquaria: Tips on Taking Light Measurements. Advanced Aquarist's Online Magazine: 7(2).

When my small laboratory needed a larger aquarium, I was shocked by prices quoted by local retailers. The cost of shipping a fragile glass or acrylic box from the mainland to the most isolated archipelago in the world (Hawai'i) greatly increases the prices on almost every commodity, including pet supplies. Since my lab does not have unlimited funds, I began researching the pros and cons of building a large plywood aquarium with the dimensions of ~96 x 24 x 24 inches - ~239 gallons (244 x 61 x 61 cm; 906 liters).

Building of this 240-gallon plywood tank will be described here.

The internet is generally a good resource of information but I did find some sites containing DIY tips for building plywood tanks that presented outdated or inaccurate information. This article will attempt to correct that information and detail the trials and tribulations of plywood aquarium construction along with updated information as well as construction time, a cost breakout and lessons learned.

After some research, I decided to go with non-pressure treated oak plywood (pre-sanded furniture grade) coated with Sherwin-Williams Tank Clad HS epoxy paint, and fasteners designed for pressure-treated deck lumber. The details for these decisions will be outlined in this article. Procedures will be discussed as well.

Safety

If you decide to take on this project, be aware that you'll deal with potentially noxious and/or flammable chemicals, dusts, and vapors, handle products capable of cutting or sticking, and use noisy power tools that will make dust, splinters, etc. Safety gear including heavy duty leather work gloves, eye, proper respiratory and hearing protection is a must. Craftsmen (two or three will be required for lifting depending upon the size) with average construction experience can do the job.

Recommended Equipment

Building a plywood aquarium could conceivably be done with just a couple of hand tools (screwdriver, hand saw) and a lot of dedication. However, these tools will make the job much easier:

• Electric drill motor (variable speed) and drill bits, drivers
• Circular saw with framing blade
• Builder's square and/or large t-square made for sheetrock
• Electric sander (vibrating/oscillating or belt)
• Paint stirrer (for use with a power drill motor), one for 1-gallon container and another for a 5-gallon pail
• 1 caulk gun

Material List

• 2 - 4'x8' ¾" oak plywood sheets
• 2 lbs. Deck Screws, 2" Grip Rite Primeguard Plus (1 pound = ~100 two inch screws). Available at Lowes and other home improvement centers.
• 2 panes 3/8" non-tempered glass (21" x 94")
• 1 tube Loctite™ Premium PL polyurethane adhesive (10 ounces). Available at Lowes and other home improvement centers, but see comments in Lessons Learned at the conclusion of this article
• Square stock, ¾"x ¾", 24 feet
• Quarter-round stock, ¾", 8 feet
• 12 tubes (2.8 oz.) silicone cement - the label must state it is aquarium safe! But try to find aquarium-safe silicone in a 10 ounce tube.

Initial Considerations

This project should not be approached in a haphazard manner. First of all, one should consider their carpentry skills. Making a large aquarium is not the place to learn how to use various hand tools.

Is there sufficient work space available - use of epoxy will require a warm, well-ventilated work place? Some of the materials used in this project are extremely flammable - keep these away from any ignition sources including natural gas pilot flames (such as that one in the water heater in your garage!).

Consider the weight of the aquarium and placement (floor joists should run perpendicular to the length of the tank). This aquarium, when full, will weight almost 2,000 pounds (909 kilograms). Hobbyists should research this further and determine if their floor is capable of supporting this much weight.

Carefully research the requirements of your aquarium - plywood and glass thickness are critical but smaller details such as fastener selection can make a major difference in the longevity of the finished product.

The following will describe the materials used in this product and various considerations:

Plywood

I used pre-sanded, non-treated, furniture grade oak plywood.

Plywood is an engineered wood product consisting of multiple layers of wood 'peeled' from a log and then glued together under heat and pressure to form a strong sheet. The grains of the individual wood layers are alternated to achieve strength and stiffness.

Plywood is available in 'interior' and 'exterior' grades. In general, the difference is the type of glue used to bond the veneers together - exterior plywood uses glue that is more water-resistant than interior grades. More importantly, exterior plywood can contain chemicals to prevent rot and provide fire, insects, and fungus resistance - these are sometimes called 'pressure treated' and may contain toxic chemicals such as copper, borate, or perhaps a mix of copper, chromium and arsenic (the use of chromium/arsenic as a preservative was banned for residential use in 2004 but is still available for agricultural and industrial use). Various preservatives include:

• CCA: Chromated Copper Arsenic
• ACQ: Alkaline Copper Quat, Types B and D
• CBA-A and CA-B: Copper Azole. Azole is an anti-fungal ingredient.
• Borates: Often seen in big box home improvement stores' lumber

Selection of treated versus non-treated wood brings up another consideration, the type of fasteners used. Some treated lumbers' chemicals are aggressive (corrosive) to fasteners (such as screws, nails, etc.), causing their integrity to degrade over a period of time. Ask your dealer his products' preservatives (often, lumber is listed a 'pressure treated' without elaboration).

Interior plywood can be used in exterior applications if (repeat if) it is properly sealed from the elements.

Plywood is available in a variety of thicknesses, ranging from ¼" to 1". See Table 1.

Be aware that these dimensions are not absolute - a plywood sheet can stray up to about 1/32" (0.03125" or 0.794mm) from the advertised thickness.

Plywood is also available in grades from A to D. Grade A is relatively free of surface irregularities such as knotholes and is generally sanded smooth. As the scale slides to D grade, more imperfections are allowed. Often, the grade of the plywood will contain two letters, such as A-C, meaning one side of the sheet is grade A and the other is C. There isn't a great deal of difference in prices of plywood according to grade. One other note - avoid structural plywood - it is composed of wood chips bonded with resins, and usually has a low grade (C-D, for example). This stuff is often used for making concrete forms.

Plywood is available in sheets up to 4 feet wide by 8 feet long. The edges from the factory are square and true - plan your work to use these edges as much as possible. The factory edges (after minor sanding to remove and burrs or splinters) should be mating edges for the bottom and side seams of the aquarium.

Fasteners

Fasteners, for our purposes, refer to wood screws. Choice of fasteners is critical - not any wood screw will do! Treated lumber can be very corrosive to fasteners and use of hot-dip galvanized or stainless steel is recommended. When purchasing the fasteners, look for those made for use with treated lumber and outdoor use (these are usually guaranteed to never rust).

Wood Glue

Various glues formulated specifically for use with wood and wood products are available. Some brands are water based while others are solvent based. I chose polyurethane glue made by Loctite™ (Premium PL polyurethane construction adhesive). This product is thick, viscous and sticky enough to hold the side panels in place while making final adjustments and driving the first screws. When dry, the product is water-resistant but not water proof and must be coated with layers of protective epoxy paint.

Glass

I decided to use glass as the viewing panes in this project simply because of its availability. As with other components, there are a couple of choices to be made when selecting glass. Most importantly, the glass must be able to withstand the force exerted by the water, which means proper selection of its thickness. A secondary but equally

important consideration is its ability to withstand the force of an external blow. For these reasons, engineers have developed guides for use in selection of aquarium glass according to aquarium depth and various safety factors.

Glass is available in two forms - tempered and un-tempered. Although tempered glass is the stronger of the two, it has a couple of major disadvantages. When tempered glass fails, it does so in a catastrophic manner, breaking into many small pieces. It is sometimes called 'safety glass' since it breaks into more-or-less square pieces where the edges aren't quite as sharp (and hence dangerous) as the razor-sharp shards of un-tempered glass.

Although tempered glass has the potential of presenting less of a hazardous when broken, its ability to disintegrate suddenly is a handicap when it comes to aquaria. Un-tempered glass is preferred since it will usually (hopefully) simply crack thus allowing a relatively slow release of water as opposed to the possibility of sudden release of hundreds of gallons of corrosive water when tempered glass fails.

A second disadvantage is that tempered glass generally cannot be drilled or edges polished after the tempering process is completed.

The most common type of glass is called 'float glass' which has uniform thickness and hence 'smoothness.' Glass is available in a variety of thicknesses. See Table 2.

Glass Safety Factor

As we know, glass is a brittle substance and has a very limited ability to bend before breaking. Forces that cause aquarium glass to bend can be internal or external, such as an accidental bump or pressure exerted by the water contained within. The thicker the glass, the stronger it is and therefore able to withstand greater forces.

The thickness of the glass you'll need is dependent upon the top to bottom depth of the aquarium, and not the length or the width. There are advantages to an aquarium of reduced depth besides construction costs - shallow aquaria are less expensive to illuminate, easier to maintain, and offer a greater surface area to volume ratio.

Engineers have calculated a safety factor for use when calculating glass thickness. Various websites offer differing advice on exactly which safety factor should be used (there seems to be a consensus that a factor of 3.8 is OK).

For this project, I decided upon glass of 3/8" thickness (0.375" or ~9.5mm). This offers a safety factor of 2.5. I obtained this information from this website:

www.theaquatools.com/building-your-aquarium

Starphire™ glass is a trade name for high clarity glass made of silica with low iron content. It is more expensive than float glass and will not be discussed further.

Silicone Cement

Silicone cement is used to adhere glass panes to the epoxy-coated plywood frame. Use only an 'aquarium grade' cement - these are engineered to withstand constant immersion in water and do not contain any biocides. It is available in pet shops and larger home improvement centers but usually in small containers. Check with a local glazier for 10 ounce tubes for use in a caulk gun if your job is a large one.

Silicone usually cures in 24 hours, but this time is dependent upon temperature, humidity and thickness of the applied product. Note that silicone can be applied at a temperature range of -35°F (-37°C) to 140°F° (60°C).

Interestingly, some manufacturers (such as DAP™) recommend a maximum aquarium size (30 gallons and water depth not to exceed 18") while others (Loctite™) do not. I suppose this is wording recommended by DAP's attorney and is meant to limit liability. This aquarium is 24 inches deep (with the glass surface exposed to a total depth of 23 ¾" even at overflow, but normally only about 21 ¾"). Further, the surface area of the glass/plywood interface is quite large and offers a massive bonding area. The plywood also braces a substantial portion of the glass. Personally, I am not concerned about label boilerplate in this case; however, this is an individual's decision and should be based on consideration of all factors.

Epoxy Coatings

Note: The following is not intended to be used in lieu of manufacturers' technical support and is intended only for informational purposes.

Glossary

There are a number of terms used when discussing use of epoxy paint, and these are a few of them:

Induction

See 'Sweat In'.

Pot Life

Period for which two mutually reactive chemicals remain useful when mixed.

Reducer

A solvent used to dilute the viscosity of a paint ("thinning"), or used to clean brushes, rollers, etc.

Reduction

Thinning of paint with an appropriate reducer. Thinning is general required only if using a paint gun to spray the aquarium. Reduction is done after the two parts are thoroughly mixed. Excessive reduction can lead to various problems, including appearance.

Sweat In

The time required for the two components of epoxy paint to react. Sweat in time is dependent upon mixing components in the proper ratio, relative humidity and temperature, but is generally 15-30 minutes. See manufacturer's directions. Sweat-in is sometimes referred to as 'induction'.

After a good deal of research, I decided on using Sherwin Williams' Tank Clad epoxy, with the standard activator. This decision was based on the product's NSF approval for potable water and good resistance to deterioration even after long-term immersion in seawater. The color I chose was Light Blue.

Sweat-in time is about 15 minutes, and Tank Clad has a pot life of about 2 hours (at ~75°F and 60% relative humidity).

These are data for this product: Sherwin-Williams Tank Clad HS

• Amine epoxy
• Recommended for Potable Water: Yes
• NSF-61 Approved: Yes
• Seawater Immersion: Yes
• Minimum Tank Size (potable): 60,000 gallons
• Coverage: ~2.5 gallons were required for this project.
• Colors: Light Blue (Sanitary White is also available)
• Approximate Price (Paint, 4 gallons and 1 Gallon Activator): $385
• Application: Roller with solvent resistant core; natural bristle brush

Other products were investigated as well, and are listed later in this article.

Epoxy paints consist of two parts - a resin (paint) and an activator (hardener) that must be mixed in proper proportions and applied within a specified time under strict conditions. Multiple layers are generally required in order to ensure a durable waterproof coating.

It is essential that an epoxy coating meets these criteria:

• Formulated for continuous immersion in water and seawater
• Good chemical resistance
• Low Volatile Organic Content (VOC)*
• Non-toxic when cured (should meet NSF/ANSI Standard 61 guidelines**)
• Offer good resistance to abrasion

These products were evaluated according to information gathered from sales representatives or the internet.

*Note 1: These products may not be available in all parts of the US, such as the metropolitan Los Angeles area where the South Coast Air Quality Management District has banned epoxies with high volatile organic compounds or VOCs. Other restrictions are in place in Maricopa County, Arizona, and Virginia northward including most northeastern U.S. states.

**Note 2: National Safety Foundation regulations for materials in contact with potable water. Paints rated for potable water may state a minimum tank size. I was puzzled by one manufacturer's recommendation for use of its product on tanks exceeding a capacity of 60,000 gallons. A representative explained that their product will slowly release organic compounds into the water and their solution to this pollution is dilution.

To put these numbers in perspective, consider a tank some 20 feet in diameter and 25 feet tall will hold about 60,000 gallons (58,718 to be exact). The square footage of coated interior (walls and bottom) will be 1,884. Hence, there are 31 gallons per square foot of coated internal surface area. The aquarium described here has ~26 square feet of surface area and a working volume of ~203 gallons, which equals 7.8 gallons per square foot of coated internal surface area (recall this tanks has 2 viewing panes). This aquarium has about 75 square feet lumber surface area (inside and outside. It has 2 glass viewing panes. Add 22.5 square feet if only one glass viewing pane is installed).

Since these coatings are recommended for large tanks, they are often not available in one gallon containers, and more often are sold in 5-gallon buckets.

Mixing and Applying Epoxy Paint

Although painting is a skill most can reasonably perform, application of epoxy paint requires an understanding of all phases in order to achieve success. Strict adherence to manufacture's mixing and application protocols are necessary to achieve a long-lasting finish. Of particular importance is temperature of the paint itself, ambient air and the object to be coated - all must exceed the minimum required temperature.

Use brushes and roller covers that are approved for use with epoxy. In this case, natural bristle brushes and covers designed for use with epoxy were used. Some suggest that brushes can be kept in a refrigerator to prevent the epoxy from hardening during periods between coats. I personally would not recommend this, as we would get into issues of pot life, temperature, moisture condensation, and so on. The brushes I found at Lowe's were about $4 each and I used them only once and did not try to save them. The same was true for the covers. These items are a minor portion of the project's total cost.

If you must reuse the brushes/covers, use xylene for cleanup. You'll have to shop around for a source as this is not normally stocked at big box home improvement centers.

Mixing

Mix each component with a low speed paint agitator, making sure no settled material remains on the bottom of the container. Paint containing high solids will likely need stirring with a stout, clean stick, such as a 1"x2". Combine the parts in the ratio recommended by the manufacturer. Thoroughly mix the two combined parts with the paint agitator. Allow proper time for the solution to react, and mix again.

Do not mix paint that has exceeded its pot life with freshly mixed paint.

Application

Stripe coat all crevices and sharp angles to prevent early failures in these areas.

Application can proceed using a roller (with a solvent resistant core), a paint brush with natural fibers, or a spray gun. I found a roller cover recommended for use with epoxy paint at Lowes.

Do not apply the paint beyond the recommended pot life.

Do not try to coat the surface in one pass - two (or more) thin coats are better than one thick coat.

Coverage

Manufactures often provide information concerning how much paint will be needed for a job, usually in the number of square feet that can be covered per gallon. Most paints recommended for use with potable water will be applied to steel tanks and are not applicable to wood (since wood is much more porous than steel). This project used about ~2.5 gallons of paint.

Curing

Once the paint has been applied, the chemical reaction of the mixed components continues until the paint is fully cured. Proper curing depends upon temperature, humidity, air flow over the painted surface, coat thickness, proper mixing, and so on. Improper curing can manifest itself in a number of ways, including discoloration (often in the form of yellowing), blushing, poor gloss, soft surface, greasy feel, poor chemical resistance and so on.

Allow the aquarium paint to fully cure for 1 week before filling.

Various coating recommendations are found on the internet, and these were investigated, and rejected for one or more reasons:

Rust-Oleum W9100

• Recommended for Potable Water: No
• NSF-61 Approved: No
• Coverage (per gallon): 125 - 225 ft²
• Colors: White, Marlin Blue (light), Safety Blue (dark), Tan, Black, Gray
• Approximate Price (Paint, per gallon): ~$85
• Approximate Price (Activator, per gallon): ~$68
• Available in 1 gallon containers
• Reason for Rejection: Not approved for potable water

Rust-Oleum W9200

• Recommended for Potable Water: Yes
• NSF-61 Approved: Yes
• Minimum Tank Size (potable water): 1,000 gallons
• Coverage (per gallon, per coat): 125 - 225 ft²
• Colors: White, Marlin Blue, Safety Blue
• Approximate Price (Paint, 5 gallons): ~$380
• Approximate Price (Activator, for 5 gallons): ~$295
• Reason for Rejection: Too expensive

Sherwin-Williams Dura-Plate 235 NSF

• Modified epoxy phenalkamine
• Recommended for Potable Water: Yes
• NSF-61 Approved: Yes
• Minimum Tank Size: >60,000 gallons
• Colors: Mill White, Buff
• Available in 1 gallon containers
• Application: Roller with solvent resistant core; natural bristle brush
• Notes: Self-priming; Cures at 0º F
• Reason for Rejection: Blue not available, white was unacceptable

Sherwin-Williams Macropoxy 646 - PW

• Polyamide epoxy
• Recommended for Potable Water: Yes
• NSF-61 Approved: Yes
• Water Temperature not to exceed 73.4º F (23ºC)
• Minimum Tank Size (potable water): 1,500 gallons
• Coverage (per gallon, per coat):
• Colors: Mill White, Light Blue, Red
• Approximate Price (Paint, 1 gallon):
• Approximate Price (Activator, 1 gallon):
• Available in 1 gallon containers
• Application: Roller with solvent resistant core; natural bristle brush
• Reason for Rejection: Not approved for use at temperatures exceeding 73.4º F (23ºC)

Sherwin-Williams Macropoxy 846-NSF

• Polyamide epoxy
• Recommended for Potable Water: Yes
• NSF-61 Approved: Yes
• Water Temperature not to exceed 73.4º F (23ºC)
• Minimum Tank Size: 1,500 gallons
• Coverage (per gallon, per coat):
• Colors: Mill White, Light Blue
• Approximate Price (Paint, 1 gallon):
• Approximate Price (Activator, 1 gallon):
• Available in 1 gallon containers
• Application: Roller with solvent resistant core; natural bristle brush
• Reason for Rejection: Not approved for use at temperatures exceeding 73.4º F (23ºC)

Sherwin-Williams Macropoxy 646 - 100

• Polyamide epoxy
• Recommended for Potable Water: No
• NSF-61 Approved: No
• Seawater Immersion: Yes
• Coverage (per gallon, per coat):
• Colors: Mill White, Light Blue
• Application: Roller with solvent resistant core; natural bristle brush
• Reason for Rejection: Not approved for potable water

Gougeon Brothers, Inc. West System

• Recommended for Potable Water: No
• NSF-61 Approved: No
• Minimum Tank Size: Not applicable - made for boat building and repair
• Aliphatic amine
• Colors: West Systems states pigments can be added to their products. See www.westsysyems.com for details
• Approximate Price (Paint, 1 gallon): ~$97
• Approximate Price (Activator, 1 gallon): ~$145
• Application: Roller with solvent resistant core; natural bristle brush
• Reason for Rejection: Not approved for potable water

Construction Time: ~20 hours

Once construction materials were gathered, cutting and assembly of the wooden box was completed in about 6 hours over the course of several afternoons. Preparation for paint and coating application added another 6 hours. Glass installation took approximately 2 hours. Pouring of the concrete pad and block/support installation added 3 hours. Final sanding, paint touchup, and bulkhead/overflow addition required 3 hours.

Construction Photos

Photographs documented this project's progression, and below are a few of them along with construction tips.

Figure 1. Pattern for cutting plywood for a 2'x 2' x 8' aquarium. Use plywood's factory cut edges when attaching panels to the bottom. Top braces should not be added until after glass is installed.

Figure 2. Important! Detail of aquarium construction.

Figure 3. Getting started. Materials are gathered and the first cut is about to be made. A straight edge is screwed to the plywood to guide the circular saw, and is off center to place the blade (with a kerf of 1/8") exactly down the center of the sheet. Mark the factory cut edges before cutting.

Figure 4. Carefully make a line a distance of ½ the plywood's thickness from the edges of the bottom, front and back panels. Drill pilot holes for the screws every 2 inches.

Figure 5. Beginning to take shape - almost ready to sand and seal. The blue tape indicates factory edges and one that needs sanding. Note the ¾" square stock running the length of the aquarium's bottom. This reinforces the joint and provides a seat on which the glass can rest during installation. The counter-sunk screw holes have not yet been filled with wood putty.

Figure 6. The fourth coat of epoxy paint has dried and the first pane of glass has been installed (the aquarium is on its side). Note the hole drilled for the overflow's bulkhead at upper rear.

Figure 7. The inexpensive stand. Not likely to make it into Architectural Digest any time soon, but it is fully functional. The notch in the support at the lower right is accommodate the bulkhead fitting.

Figure 8. The completed aquarium on its stand. A sheet of 1" Styrofoam material has been placed between the wood supports and the aquarium's bottom for cushioning purposes.

Installing Glass Panels

This is the most critical and demanding part of this project in that a fragile material (glass) must be positioned in an exact position while working against a time line (the curing time of the silicone cement). At least two workers are required, and a third would add a safety factor (but is not necessary if the seat is installed as described in Figure 2).

• Turn the aquarium face down on a suitable level work space. It is very important that all face frames are supported (see Figure 6).
• Lightly sand the epoxy paint to roughen it and create a bonding surface for the silicone glue.
• Clean the contact glass surfaces with a solvent (acetone, naphtha, etc.).
• With two people, perform a 'dry run' inserting the glass. Lightly mark with a pencil the glass' perimeter. Remove the glass and clean it again.
• Apply silicone glue to the epoxy surface where glass will make contact.
• This time, place the glass on the wooden seat created by the previously installed ¾" inch square wood stock, position the glass, and slide it off the seat into the silicone glue.
• Quickly press the glass into the glue, making sure to form a contiguous seam without bubbles. Place weights, if necessary, to keep the glass in good contact with the glue.
• Apply silicone to the perimeter of the glass where it makes contact with the epoxy coated wood inside and out. Failure to do this will result in unsightly particles getting into the seams and possibly becoming trapped.
• Allow the silicone to cure for at least 48 hours, and repeat the process for the second pane of glass (if applicable).

Final Steps - Installing the Braces

Braces along the top of an aquarium this size requires bracing in order to prevent bowing and glass and/or bond failure. Installation of braces should occur as one of the final steps since premature installation would prevent glass placement.

Do not hurry this critical step. This is what worked for me. Cut two 94.5"x3" braces, and 4-23.5" inch cross braces.

Protecting the Bottom

LeRoy Headlee of the Geothermal Aquaculture and Research Foundation (GARF) offers this idea to protect the epoxy coating on the aquarium's bottom. He recommends using egg crate grating cut to fit the tank's inside dimensions. A thin sheet of clear acrylic is said to also work well.

The Stand

This aquarium stand is a little different from most in that it will be outside (this is Hawai'i!) and was installed on a crushed lava bed. The design is based on those often seen in fish rooms with a few differences. The similarities - Concrete blocks support 2"x8" boards covered with a sheet of Styrofoam insulation. Differences - a concrete slab had to be poured to achieve a rock solid base, and the lumber is coated with epoxy paint.

I would think that an outdoor installation would not be the norm, and would highly recommend that an aquarium of this size should be placed on a slab. If this is not possible, make sure the aquarium is perpendicular to floor joists in order to achieve maximum support. Bear in mind that this stand and aquarium (when full) will weight over 2,000 pounds. Check with a professional to get an opinion on aquarium placement.

Testing for Leaks

Before proceeding, have a means to quickly empty the aquarium (such as a pump), a wet vacuum, and paper towels on hand!

Once aquarium and its stand's construction are complete, carefully level the base using a 48" construction level. Once this is done, place a 1" sheet of Styrofoam (sold in home improvement stores as insulation) and position the aquarium on top the stand and the sheet. Again, make sure the aquarium is level and use shims if necessary.

Slowly fill the aquarium with water and watch for leaks. If any are seen, note the location(s), empty the aquarium. Use silicone to plug the leaks.

Costs

As one can imagine, a project of this scope is not really inexpensive, and the cost-savings are achieved through sweat-equity. Here are the expenses involved:

Cost Breakout

• Epoxy paint: $400
• Glass: $400
• Plywood, oak, untreated (2 sheets): $85
• Lumber, 3-1" x 4": $16
• Lumber, 3-1" x 1"; 2 - ¾" quarter rounds: $15
• Fasteners, 2 pounds: $17
• Fasteners, 1 pound: $8
• Polyurethane adhesive, 1-10 ounce tube: $8 (see comments below in Lessons Learned)
• Silicone cement: $36
• Sandpaper: $8
• Paint supplies, brushes, covers, tack cloth, etc.: $60
• Miscellaneous: $300 (mostly materials for the stand, bulkhead fitting, PVC pipe, etc.)
• Total: $1,353 US

Cutting Costs

Glass was the second most expensive item for this project, and I could have reduced my cash outlay by about $200 if I had decided to use only one sheet instead of two.

Get the silicone glue in 10 ounce tubes - it is less expensive. See further comments below.

Lessons Learned

Few projects are completed without reconsideration of some construction details, and that was certainly the case with this one.

I purchased two inexpensive plastic sawhorses to support the aquarium during assembly, painting and glass installation. Don't repeat my mistake! Buy or make two heavy duty sawhorses. This aquarium gets heavy when fully assembled and the plastic sawhorses are pushed to their flimsy limits.

I got a price on the glass over the phone and did not request a written quote. When the glass was delivered, the price had jumped by $100. Needless to say I was upset and spoke with the manager. I am still attempting to get this issue resolved at the time of this writing. The fault here is mine - I had a misguided trust in the man's word. Had I obtained a written quote, I would have a much stronger position. Get written quotes!

The polyurethane has its benefits - it is very viscous & sticky and can actually hold some of the panels in place during assembly. However, there is a trade-off: When dry it is bumpy (even if it has been tooled smooth just after application). So, it is an issue of fashion or function. Your choice. Wood glue is recommended by other builders, just be aware that its use will make assembly more difficult.

Using silicone in small 2.8 ounce squeeze tubes for a project of this size is nonsense - get 10 ounce tubes made for use with a caulk gun. Squeezing the small tubes to apply a glue bead with a length of about 20 feet (for one glass pane) is tiring, the glue began to skin over in the heat of a Hawaii afternoon, and hurries the critical positioning of the glass. It is less expensive. Check with local glazier supply outlets for this. I'll repeat, fill in any gaps between the glass (inside and out) to prevent particles becoming trapped there.

There you have it - my experience in building a plywood aquarium. Now that it is done, I can use it in conducting some exciting new experiments - the real work is just getting started!

Questions? Comments? Leave messages below or email me at RiddleLabs@aol.com.

My system consists of just over 335 gallons including a 247g SPS dominated display, a 50g chalice frag tank, and a stock 75g sump. I run just about every type of lighting that is offered in this hobby. This includes a Sfiligoi 72" XR6 over my display and an ATI 10 x 39w Powermodule with a 36" ReefBrite LED strip over my chalice frag tank. Calcium / Alkalinity are dosed via a Litermeter III using Bulk Reef Supply's 2-part system. My skimmer is a Royal Exclusiv AlphaCone 300. The sump contains water, a skimmer, a heater, and a powerhead - very clean and simple. While the basis of my system is quite simple, I do really enjoy the technical side of this hobby. I have some equipment that is necessary in this hobby and some that a lot of reefers will consider luxuries. In this article, you will see several examples of both. If there are 100 ways to keep a successful reef ecosystem, I have likely tried 90 of them. And while there is not a perfect method for everyone, there are some fundamental similarities with all of the beautiful systems that we all read about. I'll get to that in a minute. But first, let talk about what got me here...

Oooooh...what is that called?

March 29, 1997 - I walked into Fishy Business in Columbia, SC and I was hooked within seconds. Like any newbie to saltwater, I asked a thousand questions and walked away with a thousand more. I ended up buying a 75g tank that belonged to one of the LFS employees about 2 weeks later. The system looked amazing to me. Well established live rock, the old school halide pendants with ballasts that weighed about 50 pounds each, and a simple sump setup. Piece of cake right? Yeah! I probably spent at least 2 hours a day at the LFS for the next 3 months asking every question in the book. The guys in the shop were very patient and they taught me quite a bit about the hobby. However, I learned on the go which, in this hobby, is not always the best way. But I learned many valuable lessons that would come in handy years later. I'm not going to waste any time on that first tank. I moved 8 times in 6 years and you can imagine the toll it took on the tank and its inhabitants. I was out of the hobby for a number of years but came back armed with a lot more knowledge.

Undisputed Champion of "Can't leave well enough alone" - not as prestigious as it sounds

Fast forward almost 10 years - ten years of reading every reef book, every thread on every website I could find, and visiting every LFS in every town I lived in. I felt like I was better educated in proper reef-keeping techniques. My wife and I walked into Fish World in Richmond, VA and I instantly got the bug again. I had met Joe Genero (owner) years before and loved the store that he and his wife Jan had built over the years. They were the first LFS in the nation to go all saltwater over 20 years ago. Joe helped me design a system that I would love. I had a laundry list of things that I wanted and didn't want. We are lucky to have an unfinished basement in our house. Both the main water line and main house drain are down there and there is tons of space that we really don't use. We went with a 150g Tall AGA and decided to place the sump and equipment in the basement - just below the tank which sits on the main floor. The tank came with a blue vinyl background, a nice stand and canopy, 2 14K 400w halides, a stock 75g sump with a refugium, a UV light, some moonlights, and a Reef Octopus skimmer. I spent the next few months stocking up on corals and fish and everything was doing very well. But my A.D.D. and (non-diagnosed) OCD kicked in and I started tweaking here and there to try and make things even better. I'm not proud of this, but here is a list of changes I made over the next 3 years (bear with me):

• Added 4 T5's to add some extra pop to the corals
• Started the Prodibio system - stopped after a few months
• Took off the blue vinyl background and painted the back of the tank black (on the outside of course)
• Bought a chiller as the halides were heating up the water
• Got a calcium reactor - got tired of manual dosing
• Decided to switch to all T5's as the power bill was getting outrageous - removed canopy for open top
• Sold the chiller since I didn't need it any longer
• Bought a bigger skimmer
• Started dosing vodka / Microbacter 7
• Took the refugium out of my sump - was a nitrate factory with the sandbed
• Got rid of the calcium reactor as I couldn't keep it dialed in - Alk was all over the place
• Switched to 2-part dosing (Bulk Reef Supply)
• Stopped dosing vodka / MB7 as my corals were starving
• Completely changed aquascape...twice...lol.
• Added frag tank

As embarrassing as all of those changes are, I feel like it's important to share them. Every time I saw a 'Reef of the Month' that I loved, I wanted to apply some of that success to my tank. Keep in mind, I was NEVER careless with the changes. Lighting changes were made very slowly as to not shock the corals, vodka dosing was done according to plan, etc. Surprisingly, I didn't lose any corals and all of my livestock thrived through all of the changes. My point is...it is VERY easy to get caught up in the latest and greatest thing. However, at the end of the day sometimes simplicity can produce the best results.

What did you just say?

My 150g had been up and running for just over 3 years, SPS was growing very well, fish were getting larger, and the tank was starting to fill in. My wife and I were watching TV one night and she looked over and said "I think we need a bigger tank"! I couldn't believe it. Being the wonderful husband that I am, I immediately called my good friend Andrew and said "I need your help fast - before she changes her mind". I knew the exact tank dimensions I wanted and Andrew had a mockup hand-sketched drawing of the stand within hours...lol. I decided to go with a 247g (72" x 33" x 24") Miracles Rimless - peninsula style tank with ¾" glass - Starphire on 3 sides. When Derek at Miracles told me that it was going to weigh 700lbs empty, I about died. Time to reinforce the floor : ). My goal with this tank build was to design a system that took all of the headaches out of the hobby (or as many as possible). I also wanted a stand that was completely different from anything I had ever seen. I travel 3+ days per week for work so I had to have a system that would be easy to maintain in my absence and easy for my wife to manage while I travel. My LFS (Fish World, Richmond, VA) helped me eliminate many of these headaches. I have 1 pump for the entire system which feeds my display, frag tank, carbon & GFO reactor, and pushes waste water to the house drain for water changes. We installed a 60g fresh water vat for top-off and a 100g vat for saltwater mix up. Water changes take me 5 minutes and I barely have to lift a finger. My LiterMeterIII handles Alkalinity, Calcium, and fresh water top-off. The only equipment in the sump is my skimmer, a heater, and a Tunze to help keep detritus from settling. My old 150g tall was a great tank but I had to use a step ladder to do just about everything. The 24" height of the new tank is great as I can actually reach things in my tank now. My friend Andrew helped me design and build a one-of-a-kind stand to hold the new tank. Okay, so he pretty much built the whole thing. I was just there to lend a hand : ). The bones of the stand are fairly standard (4x4's, cross braces, etc. - it could hold 10 tons I'm sure). We finished the outside of the stand with "Tahitian Pebbles" and a few access panels for storage and maintenance. It turned out even better than I ever imagined and I couldn't have done any of it without Andrew (thanks again my friend). It is truly one of a kind and I love it!

How do I pick a light for this thing?

I used T5's exclusively for 2 years over my 150g and had excellent results. For the new display, I did a LOT of research! I spoke with just about every lighting manufacturer you can imagine. I ran a Sfiligoi Stealth 12x54w T5 fixture over my 150g and loved the build quality, active cooling, and reflector quality. I have gotten to know Tim Lasiter (NA Distributor for Sfiligoi - Aquatics Elite) well as I bought my original Stealth fixture from him. I discussed my needs with Tim and he was able to get a package together that met every need. I decided to go with a 72" Sfiligoi XR6 (3x250w 20K's with 8 x39w T5's). The fixture itself is a work of art. It is as pleasing to the eye as it is effective for my tank's inhabitants. I really wanted to be able to dim the halides and T5's. Sfiligoi had a great solution for that as well. I have 3 ACLS ballasts (1 Master and 2 Slaves) which allow me to control each halide independently. The functionality of these ballasts is incredible! I can dim each halide, simulate east / west sun patterns, program cloudy days, and it has a "new bulb function" that ramps up new halide bulbs slowly as to not shock the corals (just to name a few of the many amazing features). The T5's are hooked up to my Apex controller which allows me to dim each bank of bulbs as well. I didn't realize just how much I missed the "shimmer" until I started running halides again. The fixture is well vented without fans so I don't have to run a chiller again - which is fine with me. The corals have never been happier.

Time for the switch...

The 700lb tank took 12 men to get into the house. My wife left town as she was too nervous to watch...lol. The stand was completed a week before the tank arrived so all we had to do was get the tank on the stand and hang the light. Many hobbyists would take the next few weeks / months to get the new tank up and running. I have never been much good at going to bed with a project looming over me, so I stayed up for 3 straight days and nights once the tank arrived. At the end of the 3 days the light was up, the tank was full of salt water, and both the 150g and the 247g were all running online together. I ran both tanks together for 7 days to allow the existing water to circulate through the new tank. I used brand new sand (seeded with existing sand from my 150g), used all rock from my old tank (plus some new live rock), and got the corals transferred over the next week and a half. My SPS did surprisingly well in the move. I was able to keep the same 75g sump in the basement. The only real change I made in the "fish room" was a larger skimmer. I upgraded from the Royal Exclusiv Alpha Cone 250 to the 300. It's more than enough skimmer for my system.

I put a LOT of time, thought, and effort into this new system. Needless to say, I spent just as much time thinking about proper rock and coral placement. The new tank is SPS dominated with a few LPS thrown into the mix as well. I had an idea of how I wanted my aquascape to look - minimalist, with plenty of open room (negative space) for the fish to swim and (most importantly) for the corals to grow. One of the biggest mistakes I see new reefers make when stocking a tank is putting too much in the tank without giving any thought as to what it may look like in a year or two (this includes both rock and coral). Like other successful hobbyists, I now research all new coral purchases to see where to put the specimen in the tank. The aquascape is pleasing to my eye and the fish swim in and out of the "islands" just as they would naturally on the reef.

Obsessive Compulsive Disorder - can be a positive in this hobby ; )

While I have never been clinically diagnosed, anyone who knows me well will tell you that I have a problem! I have zero patience for nuisance algae, coralline algae on the glass / powerheads, aptasia, or anything else in my tank that is not supposed to be there. I spend a LOT of time observing my corals. I allow my corals to tell me when something isn't right with my tank. If I observe my corals lightening or if there is a small diatom bloom, I am able to catch it early, diagnose the issue, and respond accordingly. It took me YEARS to get to that point. I used to test my water every day. Since I've gotten better at identifying small issues, my daily testing regimen has decreased to once per month. Other than water testing, here is my basic maintenance schedule:

Daily

• Check plumbing connections (takes 2 seconds)
• Syphon any detritus from frag tank
• Observe each and every coral, fish, and frag in my system
• Clean glass of display, frag tank, and sump

Weekly

• Clean powerheads with vinegar bath
• Clean overflow "teeth"
• Check all bulbs to ensure everything is "firing" properly

Monthly

• 10% water change
• Clean entire skimmer / skimmer pumps
• Clean powerhead in sump
• Completely clean out frag tank (razor blades, toothbrushes, whatever it takes)
• Inspect bulkheads
• Clean overflow and return plumbing (Loc-line, PVC)

Every 6 months

• Replace bulbs as needed
• Clean main system pump

I take a proactive approach to tank maintenance. If I could give just a few pieces of advice to folks looking to take this hobby to the next level, this would be one of them. Of course there are always things in this hobby that you can't plan for (cyano blooms, bryopsis, etc.) but if you are persistent AND consistent in your tank husbandry, you will be rewarded down the road. Set a realistic course and stick to it!

Tank parameters

• pH 8.1 - 8.3 (pH probe monitored with Apex - I recalibrate my pH probe monthly)
• Calcium 475ppm (Salifert)
• Alkalinity 8.0 dKH (Salifert)
• Magnesium 1450ppm (Salifert / Elos)
• Salinity 1.025 (Milwaukee Refractometer)
• Nitrates 0.5ppm (Salifert)
• Phosphates Undetectable (Salifert)

Tank Equipment

• Display Tank - Miracles Rimless ¾" 3-side Starphire glass Peninsula style tank (72"x33"x24")
• Display lighting - 72" Sfiligoi XR6 (3x250w 20K SE Radiums & 8x39w T5's Actinic)
• Display tank powerheads - 2 Vortech MP60ES (wirelessly controlled through Apex WXM Module)
• Frag Tank - GlassCages 3-side Starphire glass tank (40"x30"x9")
• Frag Tank lighting - ATI 10x39w Powermodule & 1x36" ReefBrite LED strip
• Frag Tank powerhead - 1 Vortech MP40 (Gen 2)
• Main circulation pump - Reeflo Hammerhead
• Sump - 75g AGA tank
• Sump powerhead - Tunze 6201
• Skimmer - Royal Exclusiv Alpha Cone 300 (with Avast Marine Swabbie)
• Controller - Neptune Systems Aquacontroller Apex (2 DC8's, WXM, VMD, pH / temp probe)
• RO/DI Unit - Bulk Reef Supply 300gpd TDS Spartan
• Dosing - LiterMeterIII - Handles Alk, Ca, and Top-off
• Remote Monitoring - Canon VB Webcam (in basement to monitor guts of system)

Mineral Supplements

• Calcium / Alkalinity - Bulk Reef Supply 2 part (Recipe 1)
• Magnesium - Kent Tech-M (Manually dosed once per week)
• Carbon - Bulk Reef Supply Rox (changed every 2 weeks)
• PO4 Remover - Rowaphos (changed every 2-3 weeks)
• Iodine - Lugol's (3 drops per day)
• Zeovit Coral Snow - As needed for cyano blooms
• Salt - Tropic Marin BioActif

Lighting Schedule (Display)

• 10AM - 12PM: All T5's - 2 hour sunrise - 0%-80% (off 15 minutes after halides come on)
• 11:45AM-7:45PM: Halides ramp up from 0-100%, full power for 5 hours, and ramp down from 100%-0%
• 7:30PM - 10:30PM: All T5's - 3 hour sunset - 80%-0%

Lighting Schedule (Frag Tank) - Reverse schedule

• 9:00PM - 10:00: ReefBrite LED's
• 10:00PM - 11:00PM: 4 T5's (Super Actinics / Blue +'s)
• 11:00PM - 4:00AM: All 10 T5's on
• 4:00AM - 5:00AM: 4 T5's (Super Actinics / Blue+'s)

Livestock

Fish

• Tongan Sailfin Tang
• Yellow Tang (2)
• Yellow Coris Wrasse (2)
• Sixline Wrasse
• Flaming Hawkfish
• Block Anthias (2 -Mated pair)
• Chocolate Tang
• Majestic Angelfish
• Black Tang
• Kole Tang
• Hybrid Powder Blue Tang
• Mimic Tang (Indian Ocean)

SPS

• Tri-Color Prostrata
• TCN Royal Blue Tenuis
• ATL Forest Fire Acropora
• Skittles Granulosa
• Bubblegum Millie

• Blue Hokei
• Darth Maul Porites
• Tyree Pink Lemonade
• Tyree Meteor Show Cyphastrea
• ORA Chips
• ORA Hawkins Echinata
• ORA Red Planet

• ORA Borealis
• Tyree Setosa
• Tyree Superman Montipora
• Tyree Sunset Montipora
• Tyree Season's Greetings Monitopora

• Bali Tri-color Acro
• Garf Bonsai
• Blue Tort
• Acropora Millepora (10+ mini colonies)
• ATL Ultimate Stag

• Ultra Blue Tenuis
• Grape Ape Montipora
• Oregon Tort
• Vivid Efflo
• Steve Elias Stag
• $500 Efflo

LPS

• Cynaria
• Scolymia (6)
• Tyree War Coral
• Bumblebee Favia
• Tyree Baby's Breath Favia
• Cosmic Swirl Favia
• Vivid Prism Favia
• Chalices (80+) - All in frag tank - WAY too many to name! I have a slight chalice addiction!

I want to thank a few people that have helped me immensely in this hobby. First, thanks to Advanced Aquarist for the opportunity to feature my tank here. A BIG thanks to Andrew Harrow - this tank would never be up and running without your help! Thanks to my extended family and friends at www.Reef2Reef.com (where I'm proud to spend a LOT of my time). Sonny Harajly (SunnyX @ www.ProCorals.com) and Derek (Miracles in Glass) both helped a great deal with my tank decision. And thanks to Joe and Jan Genero (Fish World - Richmond, VA). If you're ever in Richmond please stop by and have a look at their shop. They are both a wealth of knowledge in this crazy hobby of ours. I'm very fortunate to have a LFS of that caliber in my neighborhood. That's it! I'm excited to see the reef grow in over the next few years. I'm confident there will be some changes...lol! And I certainly hope that my tank can live up to some of the other featured tanks I've read about here.

Feel free to visit my ongoing build thread at Reef2Reef - http://www.reef2reef.com/forums/large-aquariums-180g/51736-bagbos-dream-miracles-build-powered-sfiligoi.html#post563250

Dr. Sanjay Joshi at Penn State University meets with AmericanReef.com, and examines the awesome 500-gallon reef tank on display in the Student Union. Sanjay provides details relating to the design, set-up, and maintenance of this tank, offering the home aquarist both inspiration and invaluable reef-keeping advice.

Send any comments to Americanreef@me.com or comment below this article in the comments section.

Watch The Video...

Water circulation has come a long way in recent years. Airlifts were the early years followed by in-tank impellor pumps followed by larger external pumps. Today, many companies have come out with their own variant on the propellor-based water circulation pump. With all of the options available, we're sure our readers have come out with all sorts of creative ways of creating circulation for his or her aquarium residents.

We'd love to hear and see the creative solutions that you've come up with for water circulation in your little piece of the reef. Let us know in the comments below!

The international pet product trades show in Nuremberg, Germany this past May was a smorgasbord of new marine and reef aquarium products. Some of these new products for aquariums were unique, some creative, some were great and others were really bad. All of these qualities are not mutually exclusive; many of these aquarium products were innovative and many of them deserve further attention. Obviously the question of whether a product is innovative or useful is totally subjective but I hope you'll just take this article as a mini review of products which are interesting enough to write about. If nothing else, take these products as harbingers of concepts which have wider implications for what kind of concepts can help us all to run better marine and reef aquariums.

Evo3 Titanium automatic mechanical filter roll

The Evo3 from Genesis is an interesting device which is kind of like a steampunk DialySeas machine. Instead of using a thin film membrane and water to constantly remove wastes that are dissolved in the water, the Evo3 Titanium uses a roll of filter material and a water wheel to dole out the paper filter as needed based on the amount of waste clogging up the filter paper. The way the Evo3 works is by having the filter paper wrap around a large cylindrical titanium basket. The large basket offers up a large surface area for water to flow through and be mechanically filtered. The filter basket is contained within a box of a modest size and about ten inches deep. As the filter paper around the basket becomes clogged and passes less water, the level of water in the box rises and eventually overflows via a dedicated pipe. This overflow pipe feeds water to a waterwheel which is connected to a waste filter paper collection roll. As the filter paper around the basket becomes clogged, the water level in the Evo3 box rises, overflows to a waterwheel, when it turns so does the waste collection roll which also pulls in fresh paper over the filter basket, causing the water level to drop in the box and the cycle begins all over again.

The Evo3 looks and sounds like a Rube Goldberg machine and I had my doubts when I first came across it. However, watching the Evo3 do its thing over the better part of a week gave me a sense of confidence that the design was robust and in fact, the Evo3 has been cleaning up ponds for the better part of five years. What is new is the Evo3 Titanium which features all custom made bearings, filter cage and bolts that are machined from titanium to absolutely eliminate the risk of corrosion when used in a marine water environment. My enthusiasm for the Evo3 is less about what it can do for marine fish tanks now, than what the concept of constant mechanical nutrient export can do for managing water quality of aquarium water. At $2000-2500 a piece the Evo3 is far from affordable but with future expansions on the concept of automated mechanical filtration perhaps future low nutrient SPS tanks will rely more on steam punk mechanical filtration ingenuity than starving Acros and Montis like bulimic super model corals.

The manual protein skimmer neck cleaner from Deltec is not a standalone product as much as it is a feature. Beginning very soon, selected models of Deltec skimmers will come with the option of having this manual neck cleaner which is basically a double bladed squeegee that rides the inside of the protein skimmer neck. The manual neck cleaner is rotated by twisting the lid of the skimmer cup. The first thing that struck me about the manual neck cleaner for Deltec protein skimmers is why the motorized version came before the manual one. Perhaps the motorized skimmer neck cleaner was first introduced because of the perception that a self cleaning head needed to be a very constant operation to prevent big globs of gunk from falling back into the skimmer body. Depending on how the skimmer is performing, it stands to reason that twisting the lip and neck cleaner every few days would remove a small amount of accumulated proteins which could then be easily foamed out the skimmer neck. My guess is that the increased overall performance of the protein skimmer with a cleaner neck would outweigh some of the protein skimmate which might return to the system. Also keep in mind that this Deltec feature is only the archetype of the manual protein skimmer neck cleaner and the concept is screaming to be elaborated on.

Deltec protein skimmer with manual neck cleaner.

You can picture how my eyes rolled when I was walking past the Aquatic Nature booth and a representative said he had a special fish net he wanted to show me. I could not fathom how in the world a fishnet could ever be worthy of writing about but then he pressed the net against the aquarium glass and the epiphany of this device's usefulness was immediately apparent. You see, the Aquatic nature fish net is not only clear and light colored to make less visible underwater but the fish net incorporates a thick piece of silicone between the head of the net and the end of the handle so that the net can easily be pressed against the aquarium glass to catch the desired aquarium fish and to keep it from escaping. Like Deltec's manual neck cleaner I already wrote about, the flexible fishnet from Aquatic Nature is an idea so simple it's a wonder why no one has ever thought of it. Sure the Flexi net is not going to keep aquarists up at night waiting in anxiety to get their fins on state of the art fish capture technology but, for busy aquarium shops who sell a lot of livestock the flexible fishnet is sure to be a welcome addition to the tools of the trade.

Flexible aquarium fishnet from Aquatic Nature.

The last really simple and novel product that I came across at InterZoo is actually a whole category of products. In recent years certain aquarium manufacturers began taking notice of the clip on propeller fans which are often used to increase evaporative cooling of aquarium water. These fans are clipped on the side of the aquarium and they are in your face, really taking away from the aesthetic of the aquarium. Vortex fans use a rotor which is more like an impeller in that they "pump" air through a narrow channel and direct this airflow to the aquarium's water surface. What sets vortex aquarium fans apart from regular clip on fans is that the main operating parts can hang on the side of the aquarium and their slim profile makes them easy to hide behind the aquarium. The only part of the vortex aquarium fan which is plainly visible is the small channel that is integrated into the holder on the edge of the aquarium. One model we saw even had a adjustable outlet and when angled straight down it did a fine job of rippling the surface and increasing glimmer lines. Vortex aquarium fans with the hang-on back of the aquarium design were represented by models from Dymax of Singapore, Kotobuki of Japan and several other OEM manufacturers from China.

Dymax Hang-on vortex aquarium fan.

Speaking of glimmer lines, if someone had told me that two of the more memorable devices at InterZoo would be return/draining devices I would have told them to get outta dodge. First up is the Xinout combination return and draining device from the Italian company Xaqua. The Xinout kit comes with a decent draining component that is both an ideal sized strainer and a silencing kind of drain fitting, a high quality silicone hose for the return line and a vacuum hose for the drain. Sounds pretty mundane but the real fun is where the return device comes in. With no moving parts, the return component of the Xinout pulses the water in a rhythmic motion that is based on the flow rate. There are no diaphragms and no moving parts in this thing and it's just bizarre to watch it pulse with water flowing through it and nothing but fluid dynamics producing the pulsed effect. I took a good look at the inner chamber of the Xinout and all I could gather is that there is an egg shaped cavity at the point where the water is directed at a ninety degree angle. At the moment the pulsing motion is really good at producing extra large ripples which are more aesthetic than anything, helping to increase the amount of glimmer lines coming from point source lighting. With some trial and error it might be possible to adjust an Xinout return device to pulse at a frequency that resonates with the dimensions of an aquarium to get more harmonic wave motion a la Tunze Wavebox or Vortech pump. There is virtually no other information available on the Xinout from Xaqua but I hope that it gets puts through wider aquarium use in the future so we can all learn what this thing is really capable of.

Xinout pulsing water return device.

The second noteworthy aquarium water plumbing device I spotted at InterZoo is the Mame Nano Overflow, an elegant and ingeniously designed overflow and return device. If you try to imagine the path that water takes when flowing through a conventional overflow box, and simplify that image to a single continuous tube you get the Nano Overflow. The Nano Overflow is made of three pieces of handmade glass connected together with tightly fitting vinyl tubing. The center piece of glass is actually the middle of the drain line and the only piece of the return line which are fused together by thick sections of solid glass. The return tubing has a built in venturi which is set up to draw in the air that normally accumulates on the last bend of the drain tube, same as you would on the U-tube of a classic overflow box. The venturi of the Nano Overflow can automatically restart the siphon in case of a power interruption or other siphon break. When I looked closely at the Mame Nano Overflow I couldn't help but be reminded of a classic freshwater device, the Lily Pipe made by Aqua Design Amano.

Mame Nano Overflow.

Mame only makes four products so it's such a surprise that another one of their most recent products is also quite memorable from the ocean of aquarium product from InterZoo. I saw well over 100 different LED lights, strips, tubes, lamps and just about every other form factor you can conjure up. There was a number of aquarium lights using RGB LEDs that offered a degree of custom color control but the Mame Eco-Light was a real standout effort at doing RGB reef lighting. The 49 watt Eco-Light is actually the fifth version of this particular product and the build and finish of it really made it stand out from lots of hastily completed prototypes that were the norm at InterZoo. Furthering the cause is Mame's inclusion of yellow LEDs which makes the Mame Eco-Light the first RGBY LED aquarium light and with 49 watts of diodes in less than a square foot, the power ought to be well enough for a medium sized nano reef. If you think that RGB lighting is corny, well that's because you haven't seen what RGB LEDs can do because you haven't seen Mame's RGBY Eco-Light. Furthermore, custom control of color and intensity of LEDs will become the standard for the solid state lighting in the future so we might as well figure out how to make it work for aquariums now.

Mame EcoLight 49 watt RGB LED light.

If you've been jaded by a slew of new LED fixtures that are hard to justify in the reefing budget, then get a hold of the LED tubes from Econlux that are the same T5 and PC shaped lamps you're already using. Sure you've seen fluorescent shaped t00bs with LEDs in them but these are uniquely designed to be powered by the ballast that is driving your existing HO T5 lamps and power compacts. Econlux was showing these plug and play LED replacement tubes for conventional t00b technology in a wide number of sizes and power ratings. Econlux didn't seem too interested in bringing these to market themselves as much as making them for regional lighting markets that would be OEM'd for other companies. Presumably we'll one day be able to walk into a fish store and pretend to buy a replacement in a shape we are familiar with but instead it will be loaded with the light emitting diodes as opposed to the much shorter lived fluorescents. Imagine if a single lamp could be built with a wide range of LED colors with blue and white LEDs that would accomplish similar effects as the dual colored power compact lamps. This hoop-dream of plug and play LED lamps that replace fluorescent lights could take a while to become widely available and it's viability really depends on how cost and performance of full blown LED lights change progresses in the future.

Econlux LED replacement for PC and T5 fixtures.

The last really memorable product from InterZoo that I want to tell you about is the HD touchscreen aquarium controller called the Vertex Cerebra. The Cerebra is interesting not only for it's ultra modern touch screen interface and iPad-esque form factor but also for it's applications. Much like the Apple Music store of the App store the Cerebra will have its own app market where developers will be able to sell or give away their aquarium apps. Theoretically the apps could control anything that the Cerebra interfaces with which for now is limited to the Vertex line of products which includes lots and lots of very new products. If you think about it, the Vertex Cerebra is copying Apple's iEcosystem of products and services which in itself is far from innovative. However, if you consider that it might one day be possible for an inexperienced aquarist to buy an equipment set, download an app to control it all and have it tuned to run as a Chalice coral tank or a high energy SPS tank, well that's bold new ground my friend. The concept that the Vertex Cerebra is trying to bring to the aquarium hobby will have an uphill battle of price (the Cerebra will almost surely cost more than an iPad), applications that run on popular smartphones and open software and hardware controllers that are currently under development for the aquarium hobby.

Cerebra Touch screen Aquarium Controller.

It's easy to criticize new products, products for which a market category may not yet exist. I am sometimes accused of being overly optimistic about the potential of new products for the aquarium hobby. I think it's way too easy to pick at everything that can go wrong with a certain device or invention and it's all too easy to kick the legs out from a concept before it's really been given a chance. InterZoo 2010 certainly delivered on a load of new products for use on small and large aquariums and many of them may not be revolutionary in themselves. However, the ideas these products represent can shed insight on new ways to perform common tasks like lighting a reef tank, catching a fish with a net or getting water in and out of an aquarium. I hope readers will consider the ideas that I tried to illustrate in the new products from this ginormous trade show because it'll be another two years before we get another massive wave of innovation in the aquarium hobby until the next InterZoo conference.

I want to share with you some information about a very different five-gallon nano reef that is only 6 months old. Although it's contents could fit completely into a single 5 gallon bucket, the number of reef aquarium laws which have been broken with it might one day trickle up to the largest of reef tanks.

http://www.youtube.com/watch?v=lX542hTpg-U

The full EcoReef One tank from above.

The description of this tanks sounds like a list of things not to do when setting up a reef tank: it has no live rock, no live sand, minimal filtration, no additives, the water is never tested, 100% water changes and yet this 5 gallon glass box is one of the most attractive, successful and least demanding reef tanks that I have ever set up. It is not unusual for reefers to bend the rules once in a while but most reefers would never consider completely ignoring all of these pillars of modern reefing philosophy. You might think that there must be some kind of trick to this reefing heresy but as everyone who has been stunned by this tank can attest, this little nano reef fulfills all of the basic requirements of corals and it does so with very little material, energy or maintenance and a whole lot of style. Furthermore, the extremely efficient set up of this nano reef uses so little energy that it cost about a nickel a day in electricity consumption.

Photo 1. EcoReef One is home to many diverse LPS corals.

A little background

In the early 2000s, the reef aquarium discussion was heavily slanted towards recreating the entire ecology of the reef: you had to get a ton of live rock, a huge deep sand bed, lots of janitorial invertebrates for the clean up crew and a refugium to round out the parts of the ecosystem which didn't jive with the main display. The more pods you had in your tank, the better off your reef would be because that is the way that natural reefs work. Although the majority of us were only trying to keep a nice group of corals and few reef fish in our home aquarium, suddenly it seemed like we were spending 80% of our time talking and focusing on rock, sand, crabs, shrimp, starfish, worms, amphipods, copepods, etc. Although there is nothing wrong with learning about the ecology of reef systems and being fascinated by the endless forms of invertebrate marine life, for too long many aquarist drifted away from the core needs of corals, the primary group of animals that most of us really want to keep and grow. With the idea of refocusing on corals in mind for my future reef tanks, I have been kicking around ideas for how to grow corals in an environment where the majority of the work goes directly towards benefiting my primary interest for keeping a reef tank, which is the thin veneer of living coral that we spend most of our time looking at.

Photo 2. A look at this nano reef early in it's setup when the ceramic reef was still new.

Reefing Heresy: no live rock, no live sand

When I started in the reef aquarium hobby the pure Berlin method of reefkeeping was king and my reef aquarium philosophy is still strongly influenced by those early days of wider reef aquarium success. One of the main principles of the Berlin Method is to keep the aquarium clean. Mind you it was never advocated to keep the tank sterile like marine tanks of the eighties but having few fish, infrequent feedings and having a bare bottom was key to keeping the nutrients manageable with the limited equipment that was available back then. Ever since I have always hung on to barebottoms reef tanks and because of regular success with using bare bottom instead of any kind of sand, I have long been looking for a way to do the reefscape with a structure that would be the equivalent of a barebottom. Ceramic reef shapes have been available for over a decade but until recently these have been available only from Europe and the added cost of shipping from across the pond has made ceramic reefscapes very expensive. Recently a company out of Salt Lake City called CeramEco has been making extremely gnarly and ostentatious reef shaped ceramics that are much more affordable than their European made counterparts. I truly don't have anything against live rock except that I feel that the porosity of the rock can be a drawback in the long term maintenance of a reef system. Gnarly live rock tends to accumulate detritus and nutrients over time, not to mention a large population of invertebrates which add to the bioload of the aquarium. By using ceramic reef structure that is very porous on the surface but not riddled with microcavities, I feel like there is still enough surface area for colonization by bacteria but now the nutrients that build up are in the water column or accumulating in predictable places where they can easily be removed from the system, not getting tangled up in the netherworld of live rock matrix.

Photo 3. The barebottom of EcoReef One will one day be home to a living substrate of Diaseris pieces.

Photo 4. A week after water change this little reef stays very clear through the use of a small amount of activated carbon.

Back to basics with very reduced filtration and activated carbon

I am all for having a pro-biotic environment but it is quite surprising how clean this tank stays when there is very little place for biofunk to accumulate. Since the majority of the biomass in this aquarium is coming from photosynthetic corals that are not purely heterotrophic, the diatom and filamentous algae growth is greatly reduced without any added snails or hermit crabs, just the stomatellas that hitched a ride in. Although there is some fleshy red macroalgae growth in this tank, it is periodically removed more for the shade they cause over corals than as a source of nutrient export. Aside from having an aquarium with ecology that is well balanced, a small Marineland Duetto mini internal filter serves triple duty as a mechanical filter, chemical filter and source of water motion in the EcoReef One nano reef. The Duetto has a small coarse sponge which traps large wastes and it holds one to two ounces of activated carbon which is replaced as needed to polish the aquarium water. In a tank this small a well directed flow nozzle can get all of the aquarium water moving without the need for additional water flow equipment. An adequate protein skimmer for this size of tank might hold 10-20% the volume of the tank and I find that using activated carbon is faster, more effective and a whole lot more discreet at removing dissolved organics than a puny inefficient protein skimmer.

Photo 5. 100% water changes are the norm for EcoReef One; it goes without saying that temperature and salinity are closely matched before the water change begins.

More Reefing Heresy: no dosing or testing and 100% water changes

One of the other reasons for the reduced filtration is that it is just so darn easy to do a large water change on this tank using a single bucket of water that it only takes ten minutes to "press the reset button". The EcoReef One is scheduled to get a complete water change once a week but realistically this turns out to be 2-3 a month, and sometimes less when free time is scarce. Until very recently I never would have considered doing 100% water changes with the salts that were widely available but there is something special about the ESV B-Ionic Seawater. The 4 part system mixes up completely clear in about 10 minutes and when I first started using it I noticed that corals never show the type of short term irritation that we usually experience even when doing a partial water changes. Since mixed B-Ionic Seawater appeared to be so gentle on corals during water changes, one day I tried doing a complete water change with it and minutes after refilling the tank the corals showed no sloughing and there was none of the haziness commonly seen when doing a partial water change. Furthermore, ESV B-Ionic is such a complete salt mix that without any additional dosing I noticed all the corals and macroalgae developed very rich colors and the corals inflated their tissue to a puffyness as vigorous as any I've ever seen. Finally, the water change not only resets the nutrient levels but it also completely replenishes the mineral balance and trace elements of the aquarium. I could spend a lot of time trying to test and dose the tank but complete water changes all but negate the need to keep an eye on parameters besides temperature and salinity.

Photo 6. A balanced spectrum of LED spotlighting produces much richer colors than the 20K look.

A balanced spectrum of LED spotlighting

Aquarium corals can be very healthy under a wide range of conditions but without a well balanced light source to show off the corals, no one will ever be able to see it. What makes the lighting on this tank stand out is not just the LED technology that is producing the light but the balance between LED colors including cool white, warm white, standard blue and royal blue LEDs. The main light engine on EcoReef One is a 15 watt NanoCustoms 3:2 blue to white PAR38 LED spotlight. I started the spotlighting by using the newer 21 watt version of their light but I found that it was a little too bright. With the modest lighting demands of the LPS corals in this tank I was experiencing a little bit of bleaching in parts of the tank that had hotspots of light so I downgraded the power level by 6 watts. The lighting on EcoReef One includes two accessory LED spots including a three watt spotlight with blue LEDs that compliment the royal blue color of the 3:2 PAR38 lamp quite well, as well as a 3 watt warm white LED spot which is a "PAR Booster" light which I have programmed to come on for 4-6 hours during the middle of the day. Using the accessory spotlights is mostly to boost the color rendition of the overall LED spotlighting array but it also helps to spread the brightness in a way that is more practical than using a single spotlight.

Photo 7. This tank can still get the blue light fix by manually turning off all but the blue LED spotlight.

Photo 8. There is something about LED spotlighting that shows off a lot of detail on coral.

EcoReef One uses very little power

As if having a beautiful easy to maintain nano reef aquarium wasn't enough, EcoReef One uses so little power that it may have already reached a lower limit for a tank like this. Here is the breakdown of equipment and power draw:

• Marineland Duetto- consumes 3-4 watts for the flow I have selected
• Marineland Mini shatterproof heater- rated for 10 watts but actually consumes 7 watts
• PAR 38 Spotlight - 15 watts
• Blue LED spotlight - 3 watts
• PAR Booster LED spotlight - 4 watts

Summary:

• Night time with filter and heater: 12 hrs @ 10 watts - 120 watt hrs
• Daytime with filter, heater and PAR 38 and blue spotlights: 8 hrs @ 28 watts - 224 watt hrs
• Daytime peak with all of the above plus PAR Booster spot: 4 hrs @ 32 watts - 128 watt hrs
• Total: 0.472 Kwh per day

Basically at $0.12 per Kwh in my area this tank costs $0.06 in electricity per day.

Photo 8. Later in the day the oxygen reaches such a high concentration that there is pearling of oxygen bubbles.

Some notes about this tank

What this tank doesn't have much of yet is coralline algae. Since almost no live rock was used in the construction of this reef, coralline algae spores have had to hitch a ride on the limited real estate of the coral bases. I have added one dose of Coralline algae slurry harvested from other tanks and now I am beginning to see a few isolated spots of crustose coralline algae. One of the lessons learned while setting up this reef tank is that fresh ceramic structures leach silicates in significant amount. Had I known this in advance I would have soaked the ceramic to get rid of the silicate. Since I didn't do this I was unpleasantly rewarded with diatom blooms which were sometimes so thick that I was almost discouraged by this live rock free reef system. The break in period was perhaps prolonged in this aquarium which began with very little biologically active surfaces but in time the aquarium system began to behave and respond like a typical reef system. One of the more interesting observations in this small volume aquarium is the supersaturation of oxygen after the PAR booster spot light has been on for a few hours. In freshwater planted tanks this is called "pearling" and the combination of many corals and the small biomass of red macroalgae in the small water volume increases the oxygen concentration high enough to form bubbles on the macroalgae. The formation of bubbles doesn't seem to bother anything and it's kind of neat to think the aquarium is high on oxygen for parts of the day.

EcoReef One is home to a cluster of Diaseris slices, "original" Duncanopsammia, five Scolymia australis, three Manicina areolata, one branching bubble coral, Plerogyra simplex, A couple of Echinophyllia and Acanthastrea species, a 5" polyp of elegance coral with a 1" skeleton and a pair of Harlequin shrimp, Hymenocera picta which are fed one arm of a chocolate chip starfish every 7-10 days.

Photo 9. The rulers of EcoReef One, a pair of Harlequin Shrimp.

Scaling up

Some aspects of this reduced-ecology reef aquarium scale up well to larger reef systems while some others will need modification. For example, the reef structure can easily be made of larger and larger ceramic reef structures, and the simple steampunk filtration can be made larger too. However the 100% water changes and lack of water testing that goes with it quickly becomes impractical and less economical on reef aquariums larger than about 20 gallons. For larger tanks partial water changes are more sensible and it will be necessary to test some chemistry parameters to learn how much the aquarium demands. Although the LED spotlighting works great for this small surface area with closely spaced corals, it would be inconvenient to have a huge array of spotlights on any tank longer than 3-4 feet. I currently have a 60 gallon version of this tank, EcoReef Two which will hopefully continue to push the limit of how little material or time is required to keep a reef aquarium and the corals looking good.

Photo 10. Between the tools that are used to run this nano reef and the extremely healthy corals the experiment that is EcoReef One has been very, very fulfilling.

I want to thank the many people and businesses who have contributed to this project with equipment and livestock:

CeramEco donated the ceramic VidaRock which makes up the reefscape. NanoCustoms donated the PAR 38 LED spotlight that powers this reef. ESV sent along my first sample of B-Ionic Seawater for use on this reef, now I am hooked on it. CoralMorphologic threw in several beautiful Saint Thomas anemones, Discosoma sanctithomae. The Aquarium Showroom let me frag one of their show Acanthastrea bowerbanki and a beautiful melting pot style Echinophyllia chalice corals and many of the other frags are from reefing friends Gresham Hendee of Reef Nutrition, Kevin Kohen of LiveAquaria, Jason Edward of Greenwich Aquaria, Joe Yauillo of Atlantis Marine World and Chris Bueschelle of Reefkoi Corals. Thanks everyone!

http://www.youtube.com/watch?v=fhVNbj_Spvg

EcoReef One full tank from the sides

Marine Reef Fish Husbandry - May 2, 2010

The Fish Husbandry class is now available for registration! To register, head over to www.aquaristcourses.org and click the link on the left navigation panel to the course. Inside will be registration details.

Anyone with the following questions, would do well to participate in this course!

• Are you thinking of becoming a marine fish keeper?
• Do you have experience with freshwater fish, and wonder how your skills and knowledge will translate over to the marine hobby?
• Which fish are suitable for the home aquarium?
• Do you need a protein skimmer?
• How can you best avoid disease in your tank?

This 6-week class is a meeting place where you'll learn the answers to these questions, as well as many, many more. Taught in an interactive, discussion based format, you'll be able to ask the questions that are most important to you and where you currently find yourself in the hobby. From tank selection, fish selection, basic setup to basic fish anatomy, this class will prepare you for success in the marine hobby, and enable you to make educated decisions, and avoid the pitfalls and disappointments that plague so many hobbyists, even years after investing in the hobby.

In this course we'll discuss every aspect of marine fish husbandry, from basic anatomy and biology that every aquarist should be aware of, to the do's and don'ts that are critical to your success, including but not limited to; tank setup, species selection, nutrition, managing aggression, and disease prevention. We'll also examine certain families and species in detail, and discuss why these species are (or are not) suitable for your reef tank, or for captivity in general. Upon completion, you'll be well on your way to becoming a successful marine fish keeper, and navigating the aisles of your local fish store, or the price list from your favorite online vendor will be a piece of cake!

The course starts May 2^nd and runs for 6 weeks. The cost is $100 for full access to the website, weekly live chat sessions with the instructor, 24/7 access to a forum just for this course, as well as constant access to your instructor and fellow students. Registration in the course provides lifetime access to the forums and the course materials.

Aquarium Photography - June 13, 2010

The Aquarium Photography course is now available! Registration is on the website: www.aquaristcourses.org and is $100 for a full 6 weeks of instruction.

As most aquarists and photographers have experienced, picking up a camera and taking high quality, visually stunning photographs of aquariums and their inhabitants can be quite a challenging task. There are a multitude of difficulties that a would-be aquarium photographer might encounter, including low light levels, cloudy water and reflections on the glass, not to mention the fast moving and unpredictable subject matter.

The visual appeal of a well-tended aquascape can lend itself to some truly compelling images that illustrate the dynamic nature, fantastic colours and individual personalities of the different fish and other aquatic animals.

In the Aquarium Photography course, we'll take a look at numerous aspects of successfully photographing aquariums. We'll look at; things you can do to prepare an aquarium for photography, techniques for photographing entire aquariums, composing your images, and specific methods of photographing fish and other subjects, as well as digital imaging (post-processing). We'll also delve into some of the more technical aspects of the aquarium photography process, including: lighting a tank, color balance, exposure and focusing issues.

Early in the course we will learn about cameras and other photographic equipment that is applicable to aquarium photography. For the most part, the equipment you'll need for aquarium photography is straightforward. Most well-equipped amateur photographers would likely already own much of the gear that they would need for basic aquarium photography.

This course begins June 13, 2010 and live chat sessions are 7:30-9:30 EST (4:30-6:30 PST) Sundays. The cost is $100 for full access to the website, weekly live chat sessions with the instructor, 24/7 access to a forum just for this course, as well as constant access to your instructor and fellow students. Registration in the course provides lifetime access to the forums and the course materials.

For more information on MACO, specific courses, or exactly how MACO functions, see the website www.aquaristcourses.org or email wade@reefs.org if you have questions. Registration information is available on the website through Paypal.

With the passing of another year comes the passing of a whole decade of modern reefing decade behind us. The pace of things may seem steady to the casual aquarist but when I think back to what reef tanks looked like and how they were run back in 1999, the contrast is quite apparent. I invite you to follow along with me as I take a trip down reefing memory lane and try to recount all of the major changes which have transformed the reef aquarium hobby over the last 120 months. I can't promise to recount every little detail but I think the veterans reading this will agree that most of the milestones are covered.

Although many hobbyist tanks are migrating to more efficient double-ended halides, T5 fluorescents and LEDs, for the biggest reefs nothing short of 1000 watt mogul halides will do.

This new metal halide pendant from Reefbrite also uses supplemental actinic LED lighting.

Lighting

Save for the past year, the basic technology of reef aquarium lighting has been fairly stable: fluorescent bulbs and metal halides have been the mainstay lighting source for all coral keepers, even if their forms and power factors evolved a great deal over the past decade. At the beginning of the year 2000, you were as likely to see a tank being lit with a few banks of very high output (VHO) fluorescents or power compacts as you were to see a tank using 175 and 250 watt single ended metal halide with a flat or convex reflector. For a long time most of the tanks using VHO or PC bulbs often used a retro kit to mount these lights into a canopy over the tank. Eventually the thinner PC lamps were the easiest fluorescent form factor to adapt to the aquarium striplights which most aquarists were used to using. When the last decade began Custom Sealife had been building rather heavy duty PC lights made from bent sheet metal but the market for cheaper PC lights really took off when companies like All-Glass and JBJ began to build more affordable plastic PC striplights. Since PCs were only available up to 3 feet long and VHOs were available up to 6 feet long, many small to medium sized tanks used power compacts and larger tanks tended to use Very High Output fluorescents. For years VHO and PC lighting maintained an equal presence in the hobby but when T5 lamps started being developed for aquarium use mid way through the decade, the battle of fluorescent lighting dominance quickly fell to the thinner and more efficient newcomer. The lower power demands of T5 lamps and their subsequently smaller electronic ballasts made T5s the pervasive fluorescent lighting technology in a short amount of time. Also, a high quality VHO or PC lamp that would have cost about $35-40 in 1999 can now be replaced by two T5 lamps that may cost $19 each but together with two individual reflectors they can illuminate a much broader area. At the present, it is safe to say that normal and high output T5 fluorescent lamps are the most popular entry-level reef aquarium lighting in the world but T2 fluorescent lamps are looming on the horizon. All of these mass market high intensity fluorescent lighting products have been critical to making reefing more accessible and affordable to a broader audience, helping to grow the reefing hobby and to boost the sales and development of even more powerful reef lights.

These 660 and 430 IceCap VHO fluorescent lamp ballasts were once the epitome of reef aquarium lighting, yet for being over 15 yrs old they can still drive a VHO or overdrive a T5 as good or better than any ballast.

These VHO endcaps and Mogul base sockets are slowly fading into obsolescence.

Ten years ago a metal halide lighting setup was usually more awesome in the amount of power it used and how much space it could take up than in the sheer amount of light and color rendition it could produce. Boxy metal halide fixtures from Coralife and Hamilton with isolated and widely spaced out mogul sockets backdropped against a flat sheet of aluminum were the norm. Sometimes these metal halide coffins would be paired with with some form of supplemental actinic lighting but for too long the power of the appliance was the only metric indicating how much light was actually coming from the fixture. Early in the decade the reefing hobby began to see more shapely reflectors, a wider diversity of lamps with increasingly larger Kelvin ratings as well as the emergence of double ended metal halide lamps. Reefers had long known about the exotic European "HQI" metal halide with it's curiously small size and contacts at either end. The first HQI light fixtures were very expensive German made luxury products from AquaMedic and Giesemann that cost twice as much overall as a comparable American mogul base light fixture. Like the T5 lamps, the smaller and more efficient double ended halide lamps proved much easier to manufacture into mass market fixtures and aside from the larger 400 and 100 watt lamps the double ended halide lamp is the most common form of high intensity lighting in use today.

This demonstration aquarium set up by Quality Marine shows the potential of LED lighting when many of them are used in series.

By the middle of the decade Dr. Sanjay Joshi had already performed an evaluation of various metal halide lamp, ballast and reflector combinations that were published in innumerable articles. Joshi's work showed the average aquarist that the type of lamp, ballast and reflector could all have a huge effect on the real world PAR value that would occur in an average aquarium sized volume. The Kelvin ratings of MH lamps had been tossed around very loosely by bulb manufacturers but Dr. Joshi also showed that different lamps with the same Kelvin rating label could have a vastly different PAR value and measured color rendition index. Thanks to Sanjay's mountain of metal halide lighting data reef aquarists are now much better educated about ballasts and lamps and we all know that a larger reflector is usually a better reflector for driving light down onto our corals. The past year has been good to aquarium metal halide lighting with a few new tricky ballasts and lamps. We now have available to us the TwinArc lamp from Reefbrite lighting which has dual inner envelopes that alternate with every switch of the ballast; the TwinArc costs the same as a regular halide lamp but it has envelopes that can be of the same color or in combinations of 10K and 20K. Some new electronic ballasts can adjust the driving current to sustain lamp intensity and life and other ballasts can be dimmed or switched to drive either 250 or 400 watt lamps. Also, this past year has seen the growth of yet another smaller metal halide form factor with the G12 lamps in 70 and 150 watt configurations and an HID spotlight that is 35 watts.

A new LED fixture from Marineland might be designed primarily for illumination but the thin and sleek design is hint of what reefers can expect from future LED aquarium lights. No gutters here!

It seems like LED reef lighting has been a dream on the horizon for the better part of the last ten years. The first breakthrough aquarium LED product, the Marc Weiss moonlight, may have simply been a glorified nightlight but from that humble beginning LEDs have persisted in the aquarium hobby. Few people actually use moonlights on a lunar cycle but the twilight simulation has definitely helped aquarists witness a lot more reef fish spawning. The first full fledged reef light was the PFO Solaris light and ever since the evolution of LED aquarium lights has been phenomenal and the growth of their usage exponential. The past 12 months have been particularly prolific with the emergence of LEDs in a dizzying variety of form factors including actinic striplights from Reefbrite, spotlights from Japan and NanoCustoms and the formation of Ecoxotic, an aquarium lighting company that exclusively designs and produces LED products. LED reef lighting technology is still very immature but the next two years will be transformative and I predict that we will soon experience a sea-change in how our reef aquariums are lit using LED lights.

This ancient yet functional pump timer is the ancestor to the typical random flow "wavemakers."

Two maxijet powerheads in service on Sanjay's soft coral reef tank. One uses the propeller modification and the other is using the original stock impeller.

Water Flow

If the 90's reefing discussion was dominated by how to deliver increasingly more intense light for our corals then reefing in the noughties (00-09) saw some major changes in coral husbandry with much more attention being paid to how water flow could be increased and ameliorated to the benefit of corals and the entire captive reef ecosystem. The initial dogma of water flow in mini-reef aquaria was characterized by "random, chaotic, turbulent" flow. At the beginning of the decade a mini reef tank was likely to be flowed by a battery of internal powerheads which at that time were comparatively weak. With many poorly designed pumps on the market the more pumps you had in your tank the more likely you were to suffer some kind of meltdown from your poorly epoxied water mover. Some larger tanks used the more powerful "top-loading" powerheads which transferred much less heat to the tank and although these Top pumps were fairly dependable, they were loud and required lots of maintenance to keep in peak working order. That old school water flow was provided by very quick flow alternations which was often glorified and overpriced power strips which did more to wear out our poor powerheads than to provide truly efficient and useful water movement.

A new maxijet water pump outfitted with one of the first handmade propeller modifications and an older version of the maxijet outfitted with one of the mass-produced molded maxijet mods.

The first big shift in aquarium flow pumps started to develop when DIYers began discussing the possibility of using propellers on the shaft of their impeller style powerheads. Like the propellers of boat motors it was believed that this type of water flow production would be much more efficient and effective. In early 2002 a modification kit for the little giant PE series pumps was released by Jimmy Chan of Reeftec. The modkit included a propeller and mounting bracket which allowed you to modify your PE little giant from Lowes or Home Depot into a veritable powerhouse of water flow. The little giants PE which were modified in this way were called Reeftec pumps and although the whole assembly was very bulky and the propeller was prone to shearing off from the shaft, when they worked the Reeftec pumps were the best water pushers available to reefers. The Reeftec pumps could have remained an important reefing equipment well into the future but at Interzoo 2002 Tunze announced the release of the Stream line of propeller-style water pumps and once again an innovation that had started in the DIY realm was adopted for mainstream products; reef aquarium water flow was never the same again.

This modern digital wavemaker allows the user to program an endless variety of flow patterns.

Figure 1 - Photo of the Reeftec water pump. Photo by Richard Harker

Like other first generation technologies the propeller stream pumps from Tunze drastically changed the way we push water around but they were expensive and some models had reliability issues. The bulky stream pumps had a very large motor block which was mounted to a magnet which straddled the glass and allowed the wide nozzle of water to be directed in any direction. For at least a couple years Tunze's Stream pumps were alone in the propeller water pump market but thing began to change in 2004-2005. Following on the successes of the home-made Reeftec water pumps, DIY reefers revisited the idea of making a propeller water pump, this time using the more widely available Maxijet water pump. Unlike the unidirectional little Giant PE, the maxijet has a bidirectional impeller that works to pump water no matter which direction it spins. Early maxijet modders had to develop a mechanism for making sure the impeller spins in the right direction but once this was achieved, the hobby began seeing many small scale, hand made DIY mod kits available for sale. The home made kits were affordable and they did the job of turning the workhorse Maxijet into a nice little prop pump and within a couple years the kits would be available in a mass-produced and molded form which is one of the best selling entry-level prop pumps for reef tanks today.

The original Vortech controller and one of the first 50 handmade beta MP40 water pumps.

Right about the time that the smaller MJ mod began to make waves in smaller tanks, a little company called EcoTech Marine was working on a magnetically coupled propeller pump that could push a lot of water but at the same time be very discreet within the aquarium. At the Washington MACNA in 2005 EcoTech showed off the first prototypes of it's MP40 Vortech water pump. The Vortech pump was amazing for it's size, power and unique coupling mechanism but when they told MACNA attendees that they would be forming a company that would specialize in selling only this pump for the skyscraping price of $350 a piece we all 'knew' that the Vortech pump would be short-lived. With this thought in mind I made a significant investment in two of the first 50 hand made Vortechs that EcoTech offered for sale and I am proud to say that these two Beta pumps are still running to this day. Over time EcoTech made an economy version of the Vortech, the MP20 and it also added a controller to run the pumps with multiple programs, adjustable settings and wireless sync capabilities. Despite it's high end price tag the near-ubiquity of the Vortech water pump is a testament to how much reefers have embraced propeller flow technology. Today propeller water pumps are the dominant form of water motion in most reef aquariums.

As propeller water pumps all but displaced the old style impeller water pumps as the most popular way to flow a reef tank, other pump manufacturers like Rio, Aquarium Systems Europe and Coralife have all fallen in line with propeller water pumps of their own. More recently, Tunze has completely upgraded their Turbelle Stream pumps to the Stream 2 line and Italian manufacturer Hydor released an economy propeller style water pump called the Hydor Korallia. The affordable Korallias ship with a suction-cup assisted magnetic mount that can be oriented in every direction and along with modified Maxijets the Korallias make up the bulk of the water flow pumps used in small and medium sized reef set ups.

This large external water pump from Reeflo is the dominant engine for closed loop flow systems.

Before the large Stream and Vortech pumps came along, the owners and designers of large reef tanks were still scratching their heads trying to figure out a way to install powerful external water pumps to large reef tanks in a way that would produce the most efficient water flow. The community collectively realized that plumbing a large water pump straight to and from the display tank in a "closed-loop" fashion could yield a lot of water movement. The closed-loop (as it was eventually called) was one of the only ways to add a high amount of water flow to a large reef tank without adding a lot of equipment to the display aquarium and sullying the view of the reefing scene. Early closed loop protocols called for flow-rated pumps that would simply crank out a ton of water volume through the standard Loc-Line fittings in a very static way. Once the closed-loop had become well established and widely accepted, the door was opened for companies like OceansMotions and 3iQ Ventures to develop their respective flow deflecting devices which alternated the direction in which the water current flowed. The electric OceansMotions was a popular device for medium and large sized aquariums and the SCWD (Switching Current Water Device) was widely sold for returns and closed loops alike where this device was able to do it's trick powered only by the movement of water passing through it. Both the OceansMotions and the SCWD had some issues in their early models but better engineering and development has improved both of these devices which are still used to this day. Perhaps a larger contributor to the effectiveness of closed loops is the advent of eductors and penductors. An eductor is a attachment which operates on the end of an outlet of water flow and it uses a nozzle spraying into a trumpet shape to convert the energy from high pressure water into lower pressure, higher volume water flow. Eductors were originally designed for large scale mixing applications but the design was eventually shortened into a smaller device we call penductors. A modern closed loop system will now usually employ a pressure rated pump which may deliver less water volume to the tank but when coupled with flow switching devices and eductors they can produce a very reliable water motion while still keeping most of the components outside of the aquarium.

This aquarium employs several closed loops that include flow oscillators and penductors on the outlets.

All of these changes in water movement technology for the reef aquarium undescore the shift towards the implementation of "Mass Water Movement" which is best demonstrated by the use of Gyre Flow. New School reefing dogma has moved away from a perception that random chaotic flow is desired towards an understanding that faster, more even movement of the entire aquarium volume is better for the reef, better for the corals and much easier to produce. Whereas a reef tank of the last century was usually more of a firing squad of underpowered water jets which may have been pointed in random directions and turned on and off without any rhyme or reason, in the 21^st century the design of reefing flow is much more thought out: powerheads, propeller pumps and closed loops work together to move as much water movement as possible, often in a gyre flow pattern, while using less energy and taking up much less space within the aquarium.

There are many other examples of marginal products and techniques in reef and aquarium flow and lighting but the article above does a fair job of putting together an accurate synopsis of how these two reefing realms have evolved in the past decade. Join me next time when I review how protein skimmers, additives and overall reefing techniques have changed since 1999.

Although the subject of water changes in aquaria has been one of considerable debate over the years, they are generally considered to be beneficial. Refractory compounds' (those substances resistant to traditional treatment methods) concentrations can be reduced, while desirable elements are at least supplemented. In short, we want to remove the 'bad stuff' and replace it with the 'good'.

I suspect most successful reef hobbyists adhere to a general maintenance schedule and exercise reasonable care in their husbandry procedures. But what does that mean? For example, when making water changes, how many hobbyists adjust their 'new' water to match the existing conditions within the aquarium (such as pH and other parameters)? I suspect those doing so are in the minority, and think most will judge the suitability of exchange water based on two traits - salinity and temperature. In the cases presented below, I measured and adjusted only the salinity of the 'new' water before making a water exchange. How did this affect the parameters in the aquarium? And, more importantly, did these changes become detrimental to the aquarium's inhabitants (particularly corals?).

Bingman (1995) reported coral bleaching as a result of increased water clarity (that is, increased transmission of visible and UV radiation) from either introduction of granular activated carbon or large water changes. In addition, ozone would surely aid in the removal of at least some compounds known to cause yellow water thus increasing transmission of visible/UV light. This article will revisit those thoughts, and, in addition, will quantity increased dosages of radiation bandwidths - Total UV-A + B, and PAR.

It is not the intent of this article to examine the full effects of water exchanges on water chemistry; instead our attention will be devoted to observations of the physical side effects. These will include the water column's transmission of visible light (PAR, or Photosynthetically Active Radiation) and ultraviolet radiation (UVR), water color, pH, oxidation-reduction potential (ORP), salinity, and dissolved oxygen. Here, we report the effects observed before and after two monthly water exchanges and discussion the results' implications. Our examination begins with:

Water Color

Water color can be a result of many factors, though in aquaria it is generally considered to be result of decomposing organic matter or exudates from algae. These extracellular products can include amino acids, carbohydrates, alcohols, vitamins, enzymes, volatile organic compounds, and ultraviolet radiation-absorbing substances (Fogg, 1966). The term 'yellowing' is often used to describe the apparent effect of increased water color. Besides its impact on aesthetic appeal, we know that yellow water can have an impact on light transmission through a water column and can affect PAR (particularly violet and blue wavelengths) and UVR.

The first step in a series of experiments examined water color of an aquarium containing a few fish and 'filtered' by protein skimming, mechanical filtration and light use of activated carbon. A water exchange of 40-50% is conducted on a schedule of more or less every 4 weeks. A Hach DR 890 colorimeter determined water color in platinum-cobalt units. De-ionized water was used to zero the instrument, and, since the water did not appear to contain suspended matter, no attempt was made to remove suspended solids. Figure One shows the reduction in water color after a monthly 50% water change.

Figure One. Water Color (in Platinum-Cobalt units) before and after a water change.

Technically, the pH of the water should be reported along with the color determinations since water color increases as the pH rises (Standard Methods, 20^th Edition, 1998). pH is reported below and discussed in the closing statements.

Even with diligent maintenance and husbandry, we see that the yellowing of water occurs in a relatively short period of time, and suggests that another battery of tests can proceed: That of the water column's ability to transmit visible light and ultraviolet radiation.

Photosynthetically Active Radiation (PAR) Transmission

PAR is generally considered to be composed of light wavelengths between 400 nm and 700 nm. This bandwidth includes most wavelengths known to promote photosynthesis.

Sudden changes in PAR (especially when combined with increases in water temperature and ultraviolet radiation) can potentially induce the coral animal host to eject some or all of its symbiotic dinoflagellate population in a process known as bleaching. Corals suffering from the effects of bleaching are at a competitive disadvantage and, in extreme cases, might die.

In order to test for the impacts of water exchanges on PAR transmission, a WatchDog data logger equipped with a PAR sensor was programmed to measure light intensity every 60 seconds, and the sensor was placed approximately 19 inches (16 inches of this the water column) below a reflector housing a 250-watt metal halide lamp. Baseline data was obtained before the water change was performed. Figure Two presents results typical of those obtained before and after both water changes.

Figure 2. PAR transmission increased by about 9% after a water change.

Total Ultraviolet Radiation Transmission

As with PAR, two sets of tests were conducted before, during, and after monthly water changes. A WatchDog data logger equipped with a UV sensor recorded intensity every 60 seconds. The results are shown in Figures 3 and 4.

Figure 3. Note the increased transmission of UVR at the onset of the water change beginning at ~19:30 hours.

Figure 4. Here, an even more drastic increase in UVR transmission is seen than in Figure 3.

UV-A Spectral Characteristics and Intensity During a Water Change

Ultraviolet-A radiation is that bandwidth just below the visible wavelengths and is generally described as containing wavelengths between 320nm and 400 nm. Though it is considered less damaging than UV-B and UV-C bandwidths, its presence should not be taken lightly (no pun intended). Note that there is no known UV-absorbing compound (such as mycosporine-like amino acids) that absorbs UV at the maximum wavelength generated by this and many other lamps (365 nm). In addition, many if not most plants and algae can utilize at least some portions of UV-A for promoting photosynthesis. Characterization of UV-A transmitted through the water column was made in order to determine if colored water preferentially absorbed certain UV wavelengths. This test utilized an Ocean Optics USB2000 configured for collection of UV and visible light, and equipped with a 600-micron patch cord. See Figure 5.

Figure 5. Spectral characteristics and intensity of UV transmitted through a water column before during and after a water change.

Temperature

Temperature needs little introduction. Its ease of measurement makes it perhaps the most often measured parameter within an aquarium.

Due to various constraints, water used for changes is mixed outdoors in a 55-gallon plastic drum. This drum is exposed to not only ambient out door temperatures at sea level in Hawaii, but also gains some heat from the submersible pump used for mixing. Thus, this water can be quite a bit warmer than that of the aquarium water.

Figures 6 and 7 demonstrate temperature modulations during two water changes.

Figure 6. The water temperature during this water exchange rose about 2.5ºC (~4.5ºF).

Figure 7. Heating of the water during the initial portion of this test is attributed to heat transfer from a metal halide lamp, which did nothing to cool the influx of warm exchange water. The interruption of data was due to intentional shutting down of the recording instrument in order to conserve limited memory capacity.

Water temperature was gathered using the built-in temperature sensors of pH, salinity, dissolved oxygen and redox probes connected to two Hach HQ40d multi-meter data loggers.

Oxidation Reduction Potential

Oxidation Reduction Potential, or ORP (also known as reduction-oxidation potential or redox) is the general tendency of substances within aquarium water to acquire electrons thus becoming reduced. ORP is often reported on a scale of -1999 to +1999 millivolts (mV). In aquarium water the reduction potential is the tendency of the solution to either gain or lose electrons when it is subject to change by introduction of a chemical (such as ozone). It does not characterize the capacity of the system for oxidation or reduction, in much the same way that pH does not characterize alkalinity or acidity. With that said, the measurements I've made of ocean water here in Hawaii have generally been within the range of 200 - 250 mV.

Figure 8. In this case, the Oxidation/Reduction Potential rose after a water change.

Figure 9. ORP measurements were made and recorded with a Hach redox sensor connected to an HQ40d multi-meter.

pH

pH is a logarithmic scale of… blah, blah, blah. We all know (or should) what pH is and how to interpret the measurements.

Figure 10. pH dropped during this water exchange episode.

Figure 11. In contrast to Figure 9, the water's pH actually rose after the change change.

pH measurements were made and recorded with a Hach pH sensor connected to an HQ40d multi-meter.

Dissolved Oxygen

The amount of dissolved oxygen (DO) in water is dependent upon several factors, including water temperature, altitude and barometric pressure. The amount of DO will decrease with increasing temperature and altitude. However, the most oxygen seawater can hold at sea level is generally considered to be about 7 mg/l (milligrams per liter, or parts per million), and any measurement higher than this is said to be super-saturated. In many biological processes, a rule of thumb suggests maintaining a DO of at least 2 mg/l.

Figure 12. Dissolved Oxygen concentrations fell as freshly-mixed seawater entered the system. This is not surprising given the circumstances.

DO measurements were made and recorded with one of Hach's new luminescent dissolved oxygen sensors connected to an HQ40d multi-meter and data logger.

Discussion

Table One summarizes the results observed during two water changes. All parameters, save pH, demonstrated similar (either up or down) swings.

Should we be concerned with these modulations?

pH of the water rose during the first water change, and fell the next. The exact reason(s) for dissimilar results is unknown, but the degree of shift in pH in both cases is likely of little concern. However, see comments below on the effects of pH on water color (and hence light transmission through the water column).

The same can be said for the rise in the oxidation-reduction potential. Careful observation of corals' responses to sharp decrease or increase in ORP usually includes tentacle retraction - this is usually a short-lived reaction.

The dissolved oxygen content of the water fell during both exchanges, and for good reason. This particular setup involves a closed-system aquarium and a 100-gallon sump. The pump transferring water from the sump is shut down, and most of the water is drained from the sump. Once this is completed, the 'new' water is pumped into the sump and, once full, the recirculation pump is started. During the time the sump is empty and no recirculation occurs between the sump and the aquarium, the photosynthetic alga and corals produce oxygen which accumulates to supersaturated concentrations. I'm speculating here, but if the water contains this much oxygen, then the corals' tissues probably contain much more oxygen and I have to wonder if dissolved oxygen concentrations could be used as a proxy for harmful superoxide radicals (these dangerous forms of oxygen are injurious to zooxanthellae and coral tissues). Although the water change is not directly responsible for the elevated DO concentrations, this observation suggests that oxygen concentrations in smaller aquaria, even when not strongly illuminated, could rise to high levels. This deserves further investigation.

The degree of water color, in and of itself, is not particularly important other than for aesthetic reasons. However, the results of these experiments demonstrate that increased transmission of visible and UV radiation can occur due to the decrease of compounds capable of absorbing light energy. Water color invariably increases with rising pH, and vice versa (Standard Methods, 1998). This is a potentially important clue.

Note that water color was determined via spectrometry and did not rely on any of the commercially available comparative strips specifically marketed for determination of 'yellow water'. It has been my experience that water yellowing should never advance to the degree indicated by these strips!

This leaves us with the three parameters known, when drastic changes occur, to induce coral bleaching. These are: Light energy responsible for the promotion of photosynthesis (Photosynthetically Active Radiation, or PAR), ultraviolet radiation (or UVR) and water temperature. Note that all three increased in both phases of testing. While by themselves these may not be dangerous, it is possible that these 3 parameters acting in synergy could harm captive corals (in fact, a very mild bleaching episode was observed after the latter water change. The corals lost some coloration and appeared 'washed out').

Based on this experience, I will have to become more attentive to controlling the temperature of the 'new' water, and will increase its pH in an attempt to minimize the impacts of increased transmission of visible and UV radiation due to a lower pH. Admittedly, the impact of color and pH is most likely much less than increased light transmission due to simple dilution of yellowing compounds by the water exchange, but until I get a better handle of how much of an impact, I'll play it safe.

I'm conducting some experiments on how we can eliminate the potentially negative impacts of water exchanges, and hope to have results soon. In the meantime, please direct any questions to the comments section below.

References

1. American Public Health Association, 1998. Standard Methods for the Examination of Water and Wastewater, 20^th Edition. Maryland Composition Company, Glen Burnie, MD.
2. Bingman, C., 1995. The effect of activated carbon treatment on the transmission of visible and UV light through aquarium water. Part 1: Time-course of activated carbon treatment and biological effects. Aquarium Frontiers, Summer issue.
3. Fogg, G.E., 1966. The extracellular products of algae. Oceanogr. Mar. Biol. Ann. Rev., 4: 195-212.