i see all the people makeing large tanks out of concrete which might i add is far to price and complicated i was thinking why not just use steal i work in a machine shop and i can get large sheetes of 5/16 or 3/8 steal for fairly cheap and get a bottom and 3 side weld them together and it would never break and use a sealer paint on the inside this would be far cheaper and more effient the only problem is it couldn't be a saltwater aquarium i figure i could build the tank for around 500 bucks plus the filter