[Myka]

In my experience, you can have lower flow with frags (like 30-50x turnover), but if there is a point where the corals are impeding the flow then you need big flow just to keep the water column moving. It depends a lot more on aquascaping and coral growth than anything. If there are tons of corals and little swimming space it makes sense you need bigger pumps to make it across the tank, right? Some tanks are aquascaped with a ton of water space even with big coral growth, and these tanks require less flow. My old 90 had around 50-60x turnover when the corals were smaller, I bumped it up around 100x turnover when the corals were in the 10"+ range and the difference was like night and day in color and polyp extension. I am a believer that flow is at least as important as light to SPS corals. If you have good flow you can slack in the lighting department.