On top of my substrate I have a combination of live frog moss, plants and river rocks. They hate when they get substrate on them, so it seems to help! I have 4 gray tree frogs, all on the verge of adulthood, and I have 2 water features in my new tank. One is a waterfall, and the other is just Flukers Groovy Jacuzzi Forest Terrarium Bowl X-Large Brown

The jacuzzi is nice because it has steps for them to get out of. I actually have one in each of my tanks right now (frogs in quarantine) and they all love it.