My BP lives in the basement, and my mother is always going on about humidity down there (there's a giant dehumidifier in the furnace room). So my question is, how much humidity "leaks" out of his enclosure? He's in a T10 so I wouldn't imagine a whole lot but it'd be helpful to know.

From what I can tell, when he was in a glass tank it was constantly drying out, when in a tub I never had to mist and the PVC seems to be in the middle in terms of humidity retention.