Pump to tank size

[monza]

It is sort of relevant what your tank size is and your pump but more important is how much head loss you have for that pump with "your" tank.
http://reefs.org/pumps/ -a really good head loss calculator.

(head loss is the over all flow loss from height and other plumping)

The flow depends on what you want to keep. For SPS the min. suggested is 10X your tank volume. Some peple run way higher then that.
My tank I'm planning now 250g, I'm trying to get at least 3000 gph of flow.
Two pumps from the sump, two closed loops.

Hope that helps. I've been reading way to much regarding pumps lately trying to decide which ones. It's the only decsion left and item to order for my tank.

Dave