I've got a couple 8 x 4 x 2 tanks that have 1/2" walls and bottom and a 3/4" top. They hold up great.
If you don't mind paying extra though, thicker can never hurt.
Pat
Amazon Stingrays
If you don't mind paying extra though, thicker can never hurt.
Pat
Amazon Stingrays
Seriously though I have trust in whatever they sell in theory thinking they wouldn't knowingly sell it if it would lead to bad press. Plus I couldn't build it myself for cheap enough to warrant not getting them to do it. 