Add some holes to the tub and it sounds fine to me. I live in Texas also, though I don't keep my house as cool as you, and the tank works fine for me. Right now, my cool side temps are fine. When it gets cooler, I'll add a CHE to the cool side just to bump it up a few degrees. I have most of the top covered with tin foil and a kitchen towel. Humidity is naturally in the 40s in my house, a few sprays and that bumps it up enough.