Posted: Mon Nov 26, 2007 8:27 pm
Actually, depending on how the bottom is constructed, doubling up on the Rubbermaids doesn't do much for strength---I once tried that. Most Rubbermaids don't fit exactly into one another---there's a space between the bottoms. Adding water puts pressure on the interior one's bottom, and the gap between it and the one it's in will cause the bottom to crack faster.
I'd fill the Rubbermaid (or similar container about half full (they're small and don't need to have it filled really full for now). You can build a frame to place it in if your handy to support the sides if you add more water depth. Some people have cut holes in the sides and added PVC pipe width-wise to help keep the sides from bowing out. That said, I've always found the problem to eventually be leaking from the bottoms, since they eventually cracked from the weight of the water.
"You become responsible, forever, for what you have tamed." -Antoine de Saint Exupery-