I have recently began using styrofoam peanuts in place of gravel or a false bottom, I started about 4 months ago, and they have held up great with no ill effects on the frogs. They greatly lightened up my tanks. I was trying to move my leuc tank, a 20h with 3 inches of gravel, into my new frog room and the tank weighed at least 50 lbs. I was worried the bottom was going to fall right through. The same tank with the peanuts only weights about 10 pounds. My plants root into it well too. All I do is add a 2-3 inch layer of peanuts, then a layer of sphagnum moss. They are a little more expensive than gravel but I think they are well worth the cost. If any body wants to try this use the s shaped white peanuts that don't disolve in water. If anybody has any questions feel free to ask.