I bought a Zoomed hygrotherm for my main tank, it maintains your temp and humidity. I hooked it up to my fogger and I have a red heat bulb. You just program in what you want the humidity and temp to be and it does all the work for you, even has a nighttime temp setting. It was about $65 on Amazon. A little expensive but proved to be well worth it when I had to go out of town for the night.

I had a problem with humidity in my quarantine tank though, it has a mesh top so I would lay a wet washcloth over half the tank leaving room for air to circulate.