Couple of things.
1. The top of the tank needs to be vented (roughly 80% vented) for tree frogs.
2. Looks to me like your hydrometer is reading incorrectly. At 99% you would have condensation on everything including the glass.
3. What kind of wood is that? If it is a piece of Grapevine than it will need to be removed sooner rather than later. It will mold quickly (a black/grey mold that is very dangerous).
4. Your substrate will not sustain plants long term. Should consider replacing it with something similar to ABG Mix (or ABG mix itself)
5. The Vivarium really should be taller for tree frogs. They want to climb and really do best in enclosures that are a minimum of 24" tall. I am not saying they won't survive in there, but they would appreciate more room
6. Mixing species is frowned upon. I am not going to lecture you, but be careful. You could end up loosing some or all of your frogs.
7. The lighting can also dry the air out quickly depending on what you use. You didn't mention that but if you want to know more please post the types of bulbs you are using.
Sorry to be full of criticisms. A few tweaks and you will have a great stable home for your frogs

.
Paul