I have a similar setup as you, and I have the humidity issues as well. I spray it down like you a few times a week. But, I don't spray right into the open air in the enclosure. Not sure how you do it, but I spray down specifically into the substrate, and mix up the substrate... sort to get the wet stuff on the bottom layer of substrate, and then respray the top. Basically, trying to have the substrate soak up the "wetness" so that it releases it into the air slowly. That seems to work for me.