Originally Posted by Myka

Flow through the sump has nothing to do with what type of corals are kept. As I said above, the purpose of the return pump is to feed the skimmer water to process. The skimmer can only process so much water, so increasing flow through the sump does no good. If you have a grossly over-sized skimmer then increasing the flow through the sump could possibly achieve a bit heavier skimming, but that would be negligible.

Powerheads are for provide flow for the corals and preventing detritus settling. For SPS corals you're looking in the 50-100x turnover range where LPS and softies are happy with 10-25x turnover.