sump issues

[jcmotifs]

Ok, i just got some cash so i am going to get rolling on my sump. i currently have a 30gal tank that is my fowlr. i have a 10gal tank that i want to use as the sump. its function is to hide the hang on skimmer and filter. and of course my tank is not drilled . So, i am planning on geting a hang-on overflow with a rate of 300gph and i am looking at the mag5 or mag7. i will need it to pump roughly 4-5 feet. And while i was glancing at the charts i saw the mag5 has 310gph at 4 feet but only 250 at 5. the mag 7 has 480 and 420 respectively so my question is... should my pump go over the overflow rate or under it?

 

[bs21]

return has to be equal to or under if it is pumping higher it can overwhelm the overflow.
the return GPH doesn't have to match the overflow because the overflow can only drain water as fast as the return pump provides it. If you need more flow in the tank you can supplement the return with powerheads.

 

[beckto]

When it came time to buy a return I tried to get as close to the OF (Overflow) GPH, without counting for Head loss...this way it will be about max, because if it starts at even, say 300gph Overflow, and 300gph return, by the time you account for head loss, the return would be under the overflow. But make sure the return pump isnt more than the OF. (you will spill over the display) You can put a ball valve on the return line to throttle the flow down if need be. I also learned that the OF gph is not always accurate.

 

[salt210]

the guy I bought my tank from tried to tell me that the overflows could handle a mag 36, glad they gave the pump to me and I didnt buy it. place went out of business awhile back