What type of screen is best to cover the false bottom? I found some at home depot made out of aluminum and some made out of fiberglass. The aluminum worries me becasue it is metal, and metal usually rusts. The fiberglass worries me because I don't know if it is safe under the wet conditions of a vivarium. I also found some really expensive PetScreen. I don't remember what it is made out of, but it looks more "plastic/rubber" then the other two. Thanks for any help.