I've never had an issue with humidity before the weather got cold and the heaters started kicking on. I never had to spray to keep it around 50%. Now I cannot keep it above 20% and have to spray multiple times a day to get it up to 50%. I have a 55-gallon tank with Aspen mulch. I moved the water dish to the warm side, but I cannot bring up the humidity.

Any suggestions would be helpful.