I'd be more worried about the humidity getting too low.....Water Pythons come from Marshes and are adapted to moist, high-humidity environments, much like Brazilian Rainbow Boas. Your levels sounds fine to me.....too high doesn't really factor in with these guys as long as you can provide adequate ventilation......which is why I like rubbermiads because they hold humidity so well and provide cross-ventilation with airholes in the side.