I got the hermies a 20 g.long for their Christmas gift and am in the process of setting it up. I am taking my time, as this is going to be a dream hermie home for them and me-lol. I have noticed in some pictures, that people have put artificial plants in their crabitats. After looking at many artificial plants,have noticed, all have metal in them, wouldn't this harm or possible harm the crabs, with the heat and moisture breaking down the metal?? eventually???