Looking for input on tank set up

I have a 20gLong for my female. I have the 10-20 UTH on her warm side and that side stays at 90-93. I have a blue light (not sure what its called, but it is the color of a blacklight but isnt one) that I only use if the temp in the house is below 75. With just the one UTH the temps on the cool side are 78-82 and warm side is 90-93. This last week its been 70-74 in the house because of cold weather and I left the blue light on 24/7 to keep ambient air at 80. It didn't bother her, but it does make humidity drop from 70 to 55. And I use a dimmer for the UTH because without it the UTH got up to 120F.

Oh, and the light coming in through the window is enough for them. They should be hiding in the dark during the way anyway. I feel like if you don't need the moonlight you dont need to use it. Leaving it on will make the powerbill go up a little. Mine is approx $10 difference a month with the light on 24/7 versus only using it when I need it (all other things unchanging, that is).

mabey just do one lamp put it over the water bowl to get good humidity. You will have to fill up every other day but i'd cycle it like leave it on for a while then off for a while just to regulate the humidity. Your uth should take care of the rest!
-Roman