does anyone know how to drill a tank?

I have done it once or twice. :D
Check on ReefCentral for a thread I started in the DIY section. Not sure how many pages long it is now.
What do you want to drill???

Once or Twice?:lol2: I even seen one tank drill in action! Isn't there a video of that somewhere?:yes:

What I should had said is that I was present at a tank drilling but it would not let me edit. 2 seconds after I posted, no edit for me. (not a member):doh:

I think there are a couple of videos "staring" me floating around out there. :blush:

I have a 55 and a sticker on the bottom that says its tempered and not to drill, but i was told that this means its usually just the bottoms and not the sides

talk to chrisjet he drilled mine; I think you've gotta have titanium bits and keep it wet kinda like a tile saw. Don't put a lot of pressure, kinda let the drill do the work, just apply light, even pressure on the drill. We drilled mine with water in, but don't recommend it. Also, be sure your tank isn't tempered glass, if it is, apparently it shatters everywhere.

It really isn't that hard, you need the diamond drill bits, some putty and some water... usually the sides are not tempered.

Most 55s are tempered all around. If you try and drill tempered glass, it will shatter. Then you can get a replacement pane of glass from the glass shop that isn't tempered to drill and repair it :D

I have a glass diamond coated drill bit 1 7/8" designed to drill a 1" bulkhead hole and I have the guide that makes drilling straight on easy. Whoever needs it is welcome to borrow it.

As Schwaggs said, make sure it isn't tempered first.

is there a way to tell for 100% if its tempered?

Do you know what brand it is? If it is All-Glass brand and you know how old it is, you can call them and they will tell you...

I don't know how to tell by looking at the glass...

Here is an excellent thread with a link to "justonemoretanks" advice on drilling as well as a link for AGA tank <---- tells what tanks are drillable.
http://www.atlantareefclub.org/forums/showthread.php?t=7289&highlight=glass+drilling