Bulkheads and Drain Sizes...

Go Hooter Go

New member
I want to drill my 29 Gallon tank to put an internal overflow and sump below.

The problem is that it's a cheap tank, so I am goign to drill the back wall instead of the bottom because I'm not sure if it's tempered.

So the question is...

What size hole should I drill for a 29 Gallon with about 300-400 GPH?

I am thinking of a 3/4" hole should be engough.