tank drilling

[tgoeujon]

its not labeled, or id just look up the site. i bought it at petland a few years ago so im assuming its aga

[Aquatic Addictions]

When It comes to unknown tanks take the safe route and drill the back. You can also tell if its tempered by tapping and scratching.

[fencer]

Look at this. It was a 55 gal when I tried to drill it....

http://canreef.com/vbulletin/showthread.php?t=54765

[sphelps]

55 gallon longs are 100% tempered glass, base, back and sides. This is due to the glass thickness used which requires extra strength from tempering to support the load.

You can check for tempered glass with polarized lenses as stated but you need two lenses. One on each side of the glass, then when you look though both lenses you'll see the stress structure in the glass created from the tempering process. For an example you can experiment on your car to see the difference. Windshields are not tempered but all other windows are.