Has anyone used a glass shop to have one drilled? How much did you pay? The tank I'm looking at has a tempered bottom is that a problem if I'm having a shop do it? What size overflow would I need for a 37g, what kind of return pump?
Don't have much input for ya, I'm getting ready to have a tank drilled for the first time myself...
But I would be skeptical about having a shop do it with tempered glass if it were me, but if they're willing to guarantee their work then yeah, I'd go for it. (I'd bet it'll be a lot more expensive though if they ARE willing to do it..)
I'll should have my little 30 drilled here in a few weeks.. - I'm going through the back glass instead of the bottom. (And I don't even know for sure if the bottom is tempered or not.. - I'm doing the back because of stand issues..)
No idea on costs but love to hear some responses...
Tempered Glass shouldn't be drilled as it shatters so easily.
I would go with the typical 1" draind and 3/4" return for bulkhead sizes. I think Gratefuldiver has it right, drill the sides instead of the tempered bottom.
Your return pump can range from 5x to 10x so 180gph-370gph. But I have a 55g and I'm running a 780gph. It runs my return and my skimmer via a wye and some ball valves.