I to struggled with my glass tank and temps and humidity. I got the Tropic Aire and problem sloved, that and some duct tape.
I use a human heat pad on hot side and a lamp w/ red 75 watt bulb on cool side.
Temps and humidity stay at 90-92 on hot and 80-82 on cool with 65% on hot and 50-55% on cool and 60% over all and around 78.5-81 degrees over all.
It stays pretty constant except if heat or humidity with in the house increase then some tweeking is needed. For that reason I have heat pad and light on a slide dimmer.
Check my temps with my temp gun and at the surface it will read the same as my digitals with probes that I have right on the floor surface on each end, so I assume they are both fairly correct.
So far Ozzy has had two great sheds, If I need to bump humidity up for sheds I just mist back wall of cage once or twice in 24 hr period or just stick a small pc of wet sponge in his hide with him and that takes it up to about 70-75%.
Hope this helps if ya wanna keep the glass tanks, you can make it work.
Good Luck