I want to make a paludarium and I've heard people talk about using styrofoam to build up areas or under big rocks for cushioning. I can already picture little bits of styrofoam floating in the water for the fish to snack on. I'm assuming that won't be good for them. So how do you prevent the styrofoam from flaking? All I could find was something about heat guns for smoothing carved pieces. Are you supposed to heat all the styrofoam you use? Wrap it in old pantyhose? Bury it deeply enough?
What works?
What works?