Does any know if its safe to put a couple of large pebbles in for the frogs i noticed some people use gravel in theirs i have had to change the setup for my huge whites they eat moss so we dont use it i tried the coconut stuff they try and eat that they are currently sat on a polystyrene background from an exo viv they like it but find it a little uneven.the pebbles are smooth grey ones from the beach years ago and large enough for the frogs to bask on under their light.