I've tried everything to keep heat and humidity up in my tank. I spray the bedding, wet a towel and lay over the screen top, and then place another damp towel on top of that one. Leave just enough space to fit my CHE on the warm side. I put styrofoam around the tank to hold in the heat, which helps. I wet the towels/sprayed the bedding/filled the water bowl up last night, and the humidity was up to 60%. But when I got home after work, the humidity was TWENTY-SEVEN!!!!!! I was freaking out and put another bowl of water and did the regular stuff to up the humidity. I know that keeping humidity up in a tub is MUCH easier, but I know that keeping the ambients up in a cold house may be tough. Could I still set the CHE on top of the lid of a tub if I kept it on a dimmer?