Drilling a Tank for over flow

[hawks]

I see everyone always says to drill holes in the bottom to create an overflow. For those who say that, are you doing that for every type of tank? Seems like a lot of tanks have tempered bottoms and they say NOT to drill them. Am I missing something here?
This isn't a concern for me since my tank came drilled already. I just want to understand why everyone always says drill the tank always.

Thanks,
Brian

[Tim224DT]

There are several places you can drill on a tank. When someone says to drill the tank they usually mean to drill the back wall of the tank not the bottom. You are right about tempered glass on a lot of tanks that are made.


Tim

[JennM]

Most tanks today have tempered bottoms, if in doubt, assume it is tempered and don't drill it. Even drilled tanks have tempered bottoms, they temper the glass in the factory AFTER the holes are drilled.

Back or side is the way to go for drilling, as Tim mentioned above.

Cheers,
Jenn