54G Corner Tank from Big Al's

[JetJumper]

Hey everyone.  I have a question that someone here might know the answer to.  I have a 54G Corner tank that I purchased in 2007 from Big Al's.  I am curious if anyone has had a tank similar from them and attempted to drill it?  I want to use this tank but I don't want to destroy it either by attempting to drill the bottom if its tempered.  I have drilled several tanks already and so far only 1 has been tempered (It was a 10G tank so nothing expensive - Pretty neat to watch happen but then again I don't want to kill my 54G tank)

Anyone have any experience with this style of tank?

I am going to wait and try the Polarized lens trick on a sunny day.  But with what I am using might not be 100% accurate either.

[Malyon18]

Who needs the sun, seen this a while ago and bookmarked it thinking it may come in handy some day

http://www.salt-city.org/showthread.php?t=9542

[JetJumper]

I just happen to have a few laptops at home to try this with
Thanks for that.

[laffy]

pretty neat!