Detailed information about Tunze Stream pump upgrades to increase flow
In response to the flow rate concerns raised by Advanced Aquarist's July 2011 magazine article Experimental Comparison of Measured Flow Output of Aquarium Propeller Pumps, Tunze USA has taken significant steps to improve the performance of their Stream 2 product line.
The first official upgrade is a free 24V jumper, which will bring the flow rate of model 6105 to just shy of 3300gph by increasing the rotational speed of the propeller. The new 24V jumper increases the wattage from 22-24W at 18V to 28-30W at 24V. This upgrade is officially endorsed and does not affect warranty coverage. The supplied 6105 power supply is designed to handle 50W and the motor is designed to handle 45W peak (35W constant) so owners will experience no problems with reliability. The only (expected) downside to this upgrade is a 4db increase in noise. For current Tunze 6105 owners seeking this upgrade, contact Tunze USA and provide them the model of your power supply (6101.240 or 6105.240 ... the older power supplies require different jumpers), your name and address..
Tunze 6105 owners will also have a second option to purchase a wide nozzle for the official price of $33.00 USD. This upgrade is tentatively scheduled for late October 2011.
Upcoming Changes to the Stream Product Line
Starting in November, new Stream 2 6105 will ship with both the original nozzle and wide nozzle, as well as three jumpers (12V, 18V, and the new 24V). This will allow 6105 owners to tailor their Streams to best suit their aquariums. Tunze recommends the original nozzle for longer tanks, while the new wide nozzle may be better suited for more compact aquariums.
Also, the strength of the supplied magnet of the new 6105 is reduced from accommodating 19mm (3/4") aquarium walls to 15mm (1/2"). The new magnets utilize strong ferrite magnets instead of rare earth metals due to the dramatic rise in the cost of the latter (over 600% in recent years). The older 3/4"-strength rare earth magnets will still be available but as an optional accessory for purchase (price TBD). Tunze made this decision in order to prevent cost increases to the majority of 6105 customers who do not require 3/4"-strength magnets.
The new Tunze Stream 2 6105 will be priced below $360 USD.
Finally, Tunze plans to offer free or affordable upgrades for the bigger models in their controllable Stream product line (e.g. 6205, 6305). They are currently manufacturing and testing new parts to insure performance and reliability meets their standards. Tunze would like to assure all their customers that they are working diligently to make things right and thanks everyone for their patience.