I would like to make a fake rock where my gecko could go under and on top of in my new 40 gallon breeder tank. If I used styrofoam and covered it with moarter or marine epoxy, would that be safe for my geckos? Is there a consensisus with the gecko community about which materials are safe? I wanted to make something like this http://www.csd.net/~cgadd/aqua/art_other_netmax_styro.htm but for my geckos