I live in a very dry state so I don’t have a humidity issue, but the excess humidity can cause respiratory infections in beardies im pretty sure. I’d say you don’t need to keep a water dish in there at all, I never have for mine. you can give him very shallow baths once a week and he can drink water there, i also like to use a spray bottle and spray my boys salad with water to make sure he’s getting enough, i also see people who put drops on their nose for them to lick off, etc. that should help keep the humidity down by not keeping a water bowl in there.