Help!!! The Humidity in my gabf enclosure

[Lija]

You know honestly, is it really 75% humidity in your house on a regular basis? If that is so, just cut the rectangle hole in a lid, glue in screen( you probably want to use 2 parts epoxy or similar), keep the substrate moist, but not mud like, have the water for the frog go into. And not to worry about hydrometers or humidity and if you see the substrate is drying too fast then you can cover some screen with foil or plastic ( not likely you will need it).

I'm thinking Florida is probably naturally as close as it can get to their natural habitat If you have screen in a lid and something to create a shade in a tank, I bet the guy would really apprechiate sun if you take the tub ( with the lid strongly attached ) outside for some time too, on a patio perhaps, so he won't get in a contact with local fauna.