There are steel racks out there, or you could have one built for this though...would look awesome done right, but doing it that way it would look like a bunch of water and broken glass all over your floor.
Rav
I picked up the first one in the middle of '07 for $75CAD.
Liked it so much that I contacted the gent I bought it from (his friend made it) and he had his friend build another. Can't remember exactly what I paid for that one but it was more, maybe $120CAD or something.
I just picked up another custom stand that will hold 2 X 180gal made out of 2" tube with corner bracing and everything for $150CAD.
You can't buy the steel for these prices!!