Water movement

[Reason]

I have a 125gal. drilled with two overflows . My question is what size pump is recommended to pump water from the sump back into the tank. When it was a freshwater tank i used rio,s but i'm finding that the rio's are not good pumps. Would a much larger pump work better and just split the outlet between the two return lines. I have mostly corals and want to have the proper set up. I have three powerheads inside the tank, i'm mainly concerned with the filter end of it.

[davejnz]

10x the tank size is a good flow rate through your sump IMO.You don't need alot of flow through the sump,the flow needs to be in the tank.A MAG12 rated @1200gph will flow 900gph@4' head useing 1" plumbing.That's a little under 1250gph(10x recommendation)but thats not a big deal.Your going to need 2 more powerheads as well.5 powerheads in the tank with a dual return will give you 7 sources for current.Water movement is the most important(IMO) and often overlooked aspect in keeping a reef tank.