New 90 gal. Drilling question

[JLH-l3ioCub3]

I traded my 29 bio cube for my friends 90 gal setup a couple weeks ago and I've started to hard plumb the return lines as he set it up with urethane tubing and no check valve. I noticed while looking around under the tank there is a sticker that says "this bottom is tempered glass for strength and reliability DO NOT DRILL". Well, it's drilled. Do these standard glass tanks come drilled
Or did someone drill it anyway? Is this safe? Everything seems fine with it and the bulkheads are sealed well.... Any input is appreciated!

 

[severum mama]

Tempered glass will shatter if drilled. It sounds like this might be what is known as a "reef-ready" setup, where the holes will come pre-drilled. Are there overflows built in? Can you post a photo of the tank?

 

[JLH-l3ioCub3]

I'm not sure if the guy my friend bought it from drilled it or if it came pre-drilled and the sticker is warning not to drill it again.
It makes sense that it was purchased as reef ready like you said. Otherwise, it would have shattered. Is there a way to drill tempered glass safely? I'll attach some pics anyway.

 

[severum mama]

Yeah, that is a reef ready tank, I recognize the factory-installed overflow. I would not suggest trying to drill the tank. I have never drilled a tank myself, but I had a professional do it for me once and he had to drill the back rather than the bottom. If a professional glass shop can't drill tempered glass, I'm assuming it can't be done, at least, not safely.

 

[JLH-l3ioCub3]

Yeah, that is a reef ready tank, I recognize the factory-installed overflow. I would not suggest trying to drill the tank. I have never drilled a tank myself, but I had a professional do it for me once and he had to drill the back rather than the bottom. If a professional glass shop can't drill tempered glass, I'm assuming it can't be done, at least, not safely.

Thanks for the help on this!