The only thing I would do is adding more plant/vines/branches to use more space. Almost everything is as the sides, and alot of empty space in the middle of the tank. They are tree frogs and very arboreal in nature. In most pictures you've posted of the frog, he's sitting on the ground or rock, not on a vine or something a little more tree frogy. However, if the frog is healthy and John himself said it's a good tank, it probably is very good already