By tank, do you mean it's made of glass? Chameleons should be kept in screen enclosure, otherwise there is not sufficient circulation. Also, the UV can not penetrate through glass.
You still have one chameleon, correct? Most cham owners do not use a substrate at the bottom of their cage. It can hold bacteria and lead to compaction. I use shelf liner on the bottom of mine. It's easy to clean and you can throw it away and replace it with new stuff when needed.
What exactly do you mean by moonlight? You shouldn't need to heat the cage at night. No UV is needed at night either.
I'm impressed they drink out of a bowl. Make sure you replace the water and wash it out to kill bacteria.
Good luck with your other cham, I'm sorry you lost the male.
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~Melissa
1.0 Ambanja Panther (Diesel)
0.1 African Hegdehog (Kaimah)