How to know if tank can be drilled?

[chiroken]

I'm looking into upgrading my 90g mbuna tank to a 6' tank and would want to go to a sump system so 3 sides of the tank can be used as display and to finally eliminate all those cords!

How do I know if a tank can be drilled out? I read that tempered glass can't be drilled? I've owned many tanks over 30 yrs and never really paid attention to what type of glass was used.

Do you take the tank to a glass shop to drill out the 1" hole?

Thanks.

[DragonKeeper]

Most, if not all newer tanks only use tempered glass on the bottom pane. Generally all four sides of the tank can be drilled.

[Narwhal72]

If a bottom panel is tempered glass there is usually a bright orange (Do Not Drill) sticker located between the frame and bottom of the glass. Typically for 90 gallons though the bottom is not tempered.

[pitdogg2]

both my 75's is tempered on the bottom as well as my 45 tall 30's and 55's. they also all have a sticker that say's "do not drill tempered glass" on the bottom