what size powerhead do I need?

[pontius]

in my 75 gallon, the powerhead that returns the water from the sump is 800 gph. in one corner, I have a small powerhead that runs about 80 gph (not very strong). I need another one in the other corner, any ideas how strong? it will be a maxi jet. the damsel and coral beauty are my only fish that are really strong swimmers.

 

[gilpil]

In your main tank if it is a reef, you need to turn your water over about 20X, so your powerheads would have to move about 1,100 gph. For a fowlr, 10 to 15X is recommended, so anywhere from 550 to 825 gph. This is for current and water flow, not for filtration.

 

[matti070]

or you could just look at the box. it says on most products "For tanks up to X amount of gallons."