I have an ultrasonic humidifier but it is too wet even on a timer. The ultra's are hard to get right cause they are too wet or not damp enough. I also have a "warm" humidifier but yea like Schloaty said they cook things at even a foot or so away. The plants seem to have taken no damage, thankfully. I was scared after reading somebodies post about them sitting out in dry for a day. (I don't remember who). I think i am going to build a bigger chamber soon.