This may depend as much or more on the weld strength where you join the sheets as the strength of the sheet itself. Aren't they joined with silicone caulk?
Also depends on the factor of safety wanted/needed. Commercial use is going to need a lot higher factor of safety than home use will require. Home use is pretty much up to your digression, primarily how much it would bug you to have over 950 gallons of water and a couple really pissed off fish on your living room floor.
Actually, I am kind of interested in this post. I am an aquarium owner. In our next house, we talked about putting one inside the wall. With water only, I came up with about 4,100 lbs of water weight for this example, but with rocks and sand, usually there is more weight shifted downward and less exerting on the walls. My current tank uses glass, so I am not familar with acrylic's stregnth. Does anyone have a large arylic tank and know the thickness, or what the minimum thickness should be for roughly 300 gallons or 3,000 lbs of weight with water, sand and rocks?
