Hello guys I have a sulcata tortoise and I just put new substrate to increase the humidity because the other substrate wasn't good for him. I wet the substrate but it only helped a little. Here is the picture of the thermometer and the barometer.
Those disk type meters don't work very good . They are almost always wrong . If you go to Wal-mart or Home Depot they sell a good digital meter for ten bucks . Like Yvonne said cover the enclosure with something .
I also put a wet napkin in his hide to increase the humidity. Also my houses humidity gauge says 50% so I'm sure the humidity is more in his enclosure because the substrate is wet.
I just lay a couple sheets of plexiglass that I bought from Home Depot across Elsa's enclosure when she was little. I always left open space at either end for some circulation.