Drilling tempered glass

[mamia]

I have been researching for two days about drilling holes in the bottom of an aquarium with tempered glass equals it cannot be done it will shatter. However on my drilled aquarium there is a big sticker on it that says tempered glass do not drill? Should I just assumed that someone replace the glass with non tempered glass but why would they put the sticker back on?

 

[ChrissFishes01]

Is the hole drilled in the same pane that the sticker is on? It's pretty common for the bottom pane to be tempered and for the sides to be non-tempered.

 

[mamia]

Is the hole drilled in the same pane that the sticker is on? It's pretty common for the bottom pane to be tempered and for the sides to be non-tempered.

Yes the bottom pane has the big sticker that says do not drill tempered glass, yet the tank is drilled with two holes on the bottom glass pane.
We took out the overflow box in the plumbing last week and decided not to fill it up to see if it leaks or not because we're just not sure of it's being safe passing it with a piece of glass. But I was just wondering about the whole not drilling tempered glass because it is drilled with two holes.