what type of glass is needed and is it hard to find?
i'm thinking maybe 100 gallon, but i don't know how think the glass has to be.....
pls help

For 100 gallon tank you would want the glass to be 1/2 inch thick.

Use "tempered" glass for the bottom (for strength) and regular glass for the sides. Also, it would be a good idea to pay a little more for finished glass edges, it will save your hands from getting cut when moving the glass. You should be able to find a glass distributer in the phone book.

When you silicone the glass together let it cure in a warm room for at least three days or you might have problems with leaking or it might not be able to handle the water weight when full.