Single or Double overflows for 120 gal?

[BrianO]

For a 120 gallon tank do you suggest single or double overflows?

 

[Justdrew]

Depends on the size of your return pump and the size of the pipe for the overflow. 1" drain can handle about 300 gph safely, 1.5" drain up to about 750gph safely.

Later
Drew

 

[BrianO]

Well the tank has 1 overflow 1 inch drain. I tried a Mag 9.5 and it seemed to be too much, so I put on a Rio 2500 and that worked better with keeping the water level in the sump where it should be. I tried adjusting the overflow to see if water level would change but the pump just seemed like it was pumping way too much for the overflow to handle.

 

[cpllongjk]

In sump skimmers all need different requirements for flow through the sump.

Generally I say 2-5x flow through skimmer. On my 60g tank I have about 200gph going through my sump. Most people go 2 overflows because of surface skimming. You can go 2 overflows but its not necessary for your tank.

48x24x24 right? If so 1 overflow is plenty, make it a center overflow.

 

[cpllongjk]

a 1 inch drain can handle a max of 600gph.

put a ball valve or gate valve on your return pump to dial it down. But for the return pump I would suggest no larger than mag 7.

 

[BrianO]

yeah its the 48x24x24. Thanks for the suggestions. I probably get a smaller pump and try that route for now.

<a href=showthread.php?s=&postid=14519370#post14519370 target=_blank>Originally posted</a> by cpllongjk
In sump skimmers all need different requirements for flow through the sump.

Generally I say 2-5x flow through skimmer. On my 60g tank I have about 200gph going through my sump. Most people go 2 overflows because of surface skimming. You can go 2 overflows but its not necessary for your tank.

48x24x24 right? If so 1 overflow is plenty, make it a center overflow.

 

[INNOVATOR]

<a href=showthread.php?s=&postid=14517412#post14517412 target=_blank>Originally posted</a> by Justdrew
Depends on the size of your return pump and the size of the pipe for the overflow. 1" drain can handle about 300 gph safely, 1.5" drain up to about 750gph safely.

Later
Drew

Not to steal the thread, but I talked to an aquarium manufacturer and he stated that a 6"x9" overflow with a 1" bulkhead can handle close to 700gph...seemed a little generous to me?