Overflow size?

[Notathumpa]

Is there a formula for determining the most efficient size for an OF? Maybe a % of water surface area, or a ratio or something?? The OF that I put into my 120 (72x18 SA) is an 8" round pipe into which I cut 1/4"x 1.5" slots or teeth. The pipe is attached to the bottom and extends to 1" above water surface. I run a Mag12 wide open for return and I have a 1.5" modified Durso drain. This OF is positioned at approx. the middle of the tank and draws from 360 degrees. Am I losing efficiency with this set-up and should I add OF surface, or is this OK? I know this is sketchy but it's really as basic as it sounds!

 

[chuggy]

sounds like plenty

 

[DiscoReefRover]

if it keeps up with your drain and your pump you are fine

 

[Notathumpa]

Appreciated, guys. I have seen threads regarding coast to coast OF's and wondered if there was more to it! I can see the benefits but don't think it would warrant a redo.
John

 

[Bowman]

It seems like your 8" center overflow would give you about the same surface skimming as a coast to coast being that it is in the center of the tank and pulling water from 360 degrees. and as disco said as long as your drain keeps up with your return you should be golden.