I can't see your picture well enough to find everything, but, what type of heater do you have? how big is your water dish? I see 2 dishes, can't tell which is water. I see why owners get a fogger and heater, you almost have to, to make humidity. Since your set up is vertical, you probably have branches for climbing. Waterfall sounds nice. I posted about humidity/fogger earlier to explain how I get my humidity. I have FB's with about 60 water 40 land plus extra land areas. Submersible heater, water 75-76 degrees. I cover part of tank and it creates humidity. Light is natural with small lamp beside tank.

I know your type of frog may not be a swimmer like mine, but, I found other owners giving bowl of water that does not sound large enough and their frog has to sit in it, not swim. If these are all frogs, they all need water, so, tree frogs have no choice in amount of water provided. The fogger sounds like a great measure and lights might bother frogs, too. With little water, you need a fogger. I thought that was what an aquarium was for (add water) even though your frog is a climber (people buy vertical type set up) they probably would not mind more water. Did not mean to get carried away. If you have time, its ok to write about your set up, as I can't see better from your picture. Thanks