I've got a similar thing goin on. As far as humidity try wrapping some of the screen with some plastic wrap to keep some of it in. I cut some glass that covers about 75% of it and it sits under the screen. Maybe dump some water into the substrate and stir it in a bit. I also put my heat pad under the tank because it seems to do nothing on the side. I used a heat gun to check the areas and unless you pointed it straight on, it was useless. My tank also sits on a wire rack...so i'm hoping that the pad doesnt get too hot for him. Seems pretty good so far. Keep misting too. I dont have a heat bulb for it yet, but im working on it cause I dont think the ambient temps are enough(mid 70's) Someone recomended one of those blue moonlight ones cause they dont dry out the substrate as badly. Anyone have imput on that? Maybe a ceramic heater would be better?