If you only have two snakes, I'd just mist by hand. Very few people use misting systems (or they just don't say they do). I like to physically mist my tubs by hand so that I'm getting a feel for the amount of humidity that is in the tub, instead of letting a machine take care of my snakes. I usually only have to mist each snake about twice a month before they shed... I also sometimes just move the water bowl to the warm side and evaporation does the trick.