Hey Mitch,

Pictures speak 1000 words. If you could take some pictures of the whole tank and the lid.. i may be able to help you some.

On my tanks i have about a 90% glass / vent for my lids and never have a problem with humidity.

Where in your house is the tank?
A possibility could be that a vent or fan is blowing house air into the tank and sucking out the humidity.

Generally, 90% glass lid.. + heavy misting twice a day should do it. You may consider adding a little water to the drainage layer to help maintain.

But like i said, pictures speak 1000 words

-Kevin