I sort of asked before. I have a plexy tank that is a hexagon that is 48 inches *48*48 by 18 inches tall. It is 1/4 thick. It bows a little bit when I push on it by hand.
I've found sites on volume on surface area, on figuring out how many gallons a tank is by size. I haven't found a site on pressure on volume of water, and wall thickness.
I got the living aquarium book that someone suggested, and it only has small tank sizes for pressures. I need to find out how much pressure, and if the tank is going to hold and not break.
Thanks for the help. *