FB filters are great additional biofiltration for you, but have the ability to completely sap the oxygen from the system in short order if they are the only source of biological filtration, IME. Due to their basically unlimited colonizing capacity, the limiting factor becomes oxygen. As long as you make sure you have a tower of bioballs for the water to trickle over, or a powerhead running a large venturi, or something of the like in your sump, you should be fine.
As far as the pump being the right size, each FBF is going to be rated for a certain flow rate. If the pump is too large, you will end up shutting the valve back to keep it from blowing sand out into your tank, and it can cause more wear and problems for the pump. It's usually recommended to just buy the pump rated how they recommend, IME.
Each tank will have a powerhead in it, and the sump will have an eair stone to help the filter media move about, (I am using a fluid balanced filter media that basically cleans itself, hopefully)
I think you are right about the power head, I'll keep that for increasing the flow-reate.
cheers barbie
rob
The perfect white lie..."Of course I didn't pay that much for the fish honey"
