Tempered or not tempered

[SilverSurfer]

So first I want to thank Sam for coming over and all the great advice on plumbing options as well as informing me of synergy. Ok so my question is does anyone know a way to tell if aquarium glass is tempered or not? I bought a 135 gallon glass aquarium second hand. I believe the glass is half inch thick and want to drill the back glass for overflows/returns and obviously don't want it to explode while doing so as Im thinking that may impede its ability to hold water..... :lol:. Look forward to hearing what everyone has to say. Thanks.

 

[Mccoc033]

I'm pretty sure that back glass is usually not tempered, but I could be wrong. Bottom glass is sometimes tempered I think. Again, I'm not super sure if that is true.

 

[SilverSurfer]

Yeah thats what I was thinking too, thanks. Guy said he had the tank for 10 years though it looks brand new. He also said the guy he bought it from probably had it 10 years lol.

 

[SkyShark]

There is a way to tell using polarized sunglasses. I don't remember the trick exactly, but you should be able to find it pretty easily with a little googling.

 

[SilverSurfer]

Awesome ty for the tip

 

[Shaunv]

http://www.ehow.com/how_5759804_tell-glass-tempered.html

 

[SilverSurfer]

Thanks for the link the edges are rough and therefore I assume non tempered also no stamp, awesome thanks so much super helpful.