Flow in 100g tank

[lizri]

I'm setting up a 100(ish) gallon tank (48" long x 18" wide x 26" tall) and had a question about flow. This will be my first drilled tank and we are drilling it and installing the overflow. The tank has two existing 1.5" holes, one in each upper corner (top left, top right). Tank's previous owner was running one as overflow and one as return. I will be drilling it for a 3 hole return (Bean Animal). The tank will be primarily LPS. My question is: should I use the two existing holes as dual returns and drill the overflow in the center, or place the overflow in the corner (drilling two new holes and utilizing one existing hole) and use the other corner as a single return? I have two Jebao PP8's with wavemaker controls on the way, and the return pump is a Jebao DCT 8000 with controller. My concern is having too much flow going on for my LPS dominated tank. Please advise. :reading:

 

[lizri]

Oops -- Should read "3 hole overflow", not "3 hole return."

 

[mcgyvr]

IMO...
Use 2 existing holes for return..
With an almost coast-coast overflow box between them.. 3 new holes centered..

 

[nereefpat]

since you have to drill the tank no matter what, I would definitely use the two in the corners for returns. Then drill three holes in the center of the tank.

 

[lizri]

Centered overflow it is! FWIW, my overflow box is 18" long and rated for 1500 gph. Thanks for the input! Much appreciated.