This guy's thread on RC shows that he had a 48" x 72" tank made with 1/2" glass. I'm not sure of the height...I think 20-22". I would think a 36" x 36" tank at a height of 18" would be ok with 1/4" glass.
Everywhere I've read said as long as you don't go above 18", 1/4" glass is ok. But people are makin' me nervous
