Ok I understand. Im not a big fan of that particular filter, it is ineffective imo.
I suggest reading a thread here on sponge filters for all your tanks. Waterdogs thread has lots of info and should be a sticky.
They can all be run off 1 or 2 pumps depends on size and are really cheap. I have 15 tanks on 3 pumps and adjust the flow for each one to exactly what is appropriate, they don't need to be raring along just a nice steady flow of bubbles. If any of my hobs break down they are thrown out and replaced by a sponge filter. They work great ime and just make sure you squeeze them out in old tank water every week to keep good bb on them.