Opinion on overflows

[cdub]

for my new garage tank room i am planning on having a 55 gallon rubbermaid stock tank as the sump, with another one above it as a refugium/frag tank.

i was wondering if there is a difference between having the top tank drilled in the bottom to over flow vs. drilled on the side of the tub.

 

[slayer]

if you drill in the side, your pretty much stuck (unless you use an elbow) as to the height of the water in the tub...if you drill at the bottom you can change the level of the water in the tub by increasing or decreasing the pipe height....also your gonna have more head pressure with it drilled in the bottom (means more flow).. another problem with drilling at the bottom is that you'll need to cut a hole out in the stand to allow it to exit the bottom of the sump..