Overflow / Return Sizes

[thewackyreefer]

Need some quick advice...

Ordering a custom Leemar tank that is going to be 24" x 18" x 20" with an external overflow.

I would like to only have 1 return hole drilled and 1 overflow hole in the external.

2 questions...what size bulkheads should I use in the overflow and for the return? And how far from the top and right side should the return be on the back?

Thanks!

 

[Blackhawk Fan]

I would have the overflow centered with a 1" drain and a 3/4" return.