American Green Tree Frog tank setups, your input?

They all apear fine to me, except the ten-gallon. Gravel is a no-no when keeping most frogs and the only frogs that can be keep in tank with it are totally aquatic species such as Xenopus, Pipa, and so on. The reason being, non-aquatics have the potential of swallowing it and having a gastrointestinal impaction, which can lead to death.
Also that gravel is way too think and will only serve as a breeding ground for bacteria.

I use stone and water as my substrate as well, BUT I use larger rounded stones with about an inch or less of water so it isn't too deep for them. I also use a water pump to keep the water from becoming stagnant. This seems to work quite well, though the humidity isn't as high as I had hoped... I just have to mist the tanks daily. I completely rinse and change the water every 2 to 3 weeks.

I think you need a lot more branches and perches. And welcome to the forum.

The 10 gal is only for the frogs which are still tadpoles. Once they have all 4 legs and sticking to the walls, they will be moved. Since they do not eat for about a week after leaving the water, I do not have to worry about them eating the gravel. In the 20 gal, when I find better branches that wont rot, I will add them. The grass and pumpkin seeds I planted should cover most of the lower half of the tank. =)

I like the decorations painted on the back wall. (I assume the paint is on the outside of the glass?) What kind of paint did you use, and do you have any general pointers? I usually get laze and just spraypaint the back of the glass one flat color, but it hadn't occured to me to try detailing.

I use acrylic paint, and it is on the outside. If you want to change it, it comes off with a wet sponge, but its pretty good against normal wear n tare. It is on the long side of the tank. just grasses, tree branches and the such. The best part is, that with a light on for the frogs, the other side looks really cool. The paint is layered and it shows through really nicely. From the inside it looks a little plain, bu the frogs don't mind.

more branches and plants and grass growing.

added bigger rocks instead. do tadpoles need warm water?