Never figured mine up, but I have a sump rated for up to 175 gallon I believe. I have a 500 GPH return pump in the sump, 2 MJ 900's, a UV with a small pump on it, and a HOB dual Marineland Bio wheel that houses my Chaeto.
Sounds like a lot, but I have the power heads timed through my Apex Aquacontroller. Seems to work out pretty well.