plexiglass

Okay, what is the difference between the acrylic that they make tanks out of and the plexiglass you get at home depot? Can I make dividers with small holes from the plexi or should I figure its too expensive and possibly deadly to the fish?

Anyone have a small piece for free? One of the tank's middle brace broke while I was cleaning, and I would like to glue them back together with a piece of acrylic or plexiglass..I'm not looking for a big piece.. I just need some spare pieces you can give me.. I can pick up at CCA meeting.. For...