Originally Posted by Shetland James
I have a 4watt second hand RENA filter - it works great but maybe too great. It's got quite a strong flow coming from it and I'm worried that this might hamper my Fighters movements in the tank.
Is there any creative, home-made ways of limiting the filter's output?
You could always try a heavy duty light dimmer. That said a frequency drive type motor controller would probably be what you want. I'm guessing that all of these aquarium devices use induction motors. Certainly most back of tank type pumps are. Changing the frequency would change the speed of the rotor and therefore the flow rate. Now, such things can be purchased, at a cost, but for the power levels needed for aquarium gear, they can be built very cheeply if you can read a schematic.