What powerhead to use?

[suv]

Im wondering what size power head to use as my return pump? Tank is 90 gal. and sump is about 10-12 gal.

 

[wangotango]

How many GPH does your overflow handle? You want a pump that will match that after it compensates for the head-loss. So if your overflow drains 600gph you're going to want a pump that pumps about 700gph at 0' head to match the 600gph once it's pumped back up.
I'm using a mag-7.
-Justin

 

[suv]

Is there a formula to figure the gph, of an overflow?

 

[lion_crazz]

What size hole is your overflow box? What size bulkhead? That will tell us how much it will drain.

 

[suv]

I just got to work and don't have it in front of me, but I belive it is 1.25" it could be 1" though(but I don't think so).