I've never tested the strength of glass....but...
I have a 55
gal tank with stand, the stand is not solid at the top, it's like...a frame and the fish tank sits into it perfectly but the bottom of the tank is open to the air, if that makes sense? I mean, it has no support other than the frame that goes all the way around the edges and the bar that goes along the middle.
My question is, if you can picture all that, is this enough support for me to turn that 55gal into a reef? I know that it will hold the water fine, but my worry is the sand and live rock...
Maybe I'm just being paranoid.