Good call, Kurt. When I spoke of gravel, I meant of the larger variety, something that would not be as easily ingested as standard aquarium gravel. The local hardware store by me sells very large gravel (golf ball size, which would be much harder to ingest). I have to say though, I really am not the biggest fan of piling gravel in one end, it's just a really easy way to make a land/water setup. The downside of doing the gravel thing is that bullfrogs are large, and will rearrange setups like that when they move around, so keeping the gravel piled up in one side requires constant "landscaping". The turtle docks or cork bark/driftwood land areas are much better. Also, speaking of frog safety, I never mentioned before that if using silicone to glue anything to the tank let it cure for at least 36 hours so that any toxic fumes are gone, otherwise it can be harmful to the frog. Once silicone is cured it is harmless to any terrarium occupants (as long as you use 100% silicone sealant). Also make sure to do any glueing in a room that the frogs are NOT in, preferably outside. I hope that clears things up.