If your vet specializes (was TRAINED) in reptiles, he "should be" reliable for information, but if you just took your snake to a vet willing to SEE reptiles, they are often not up on proper husbandry...& keep in mind how MANY kinds of exotics there are (reptiles +++). Anyway, the larger water bowl will slightly raise the humidity just by being in there-but what kind of enclosure is this? or rather, is there a screen top? (how much ventilation there is will determine how much humidity it retains...the more air flow there is, the more it dries out, especially because of the heat)