I have a terrarium housing a whites tree frog and was wondering what type of ground cover most people use over their substrate. I purchased "tropical moss" from blackjungle a month or so ago, but it just doesn't seem to be taking all that well. I think it requires too high a humidity, which is leading to mold outbreaks in the tank. Quite frankly I can never get moss to really thrive in there for some reason. Maybe my water is too hard or the UVB bulb is not intense enough or whatever. Do you use moss, rock, river stones, leaf litter, bark etc or none at all?