Hello, I have a baby sulcata tortoise and I was wondering where exactly I should put the hydrometer in his cage at? I have three digital readers, I have one on the cold side of his cage(by cold I mean 75-80 degrees), one on his hot, and then one half way up his cage in the middle. All three of them read at different levels. The cold one being at around 85% the hot one at 75% and the one in the upper middle at like 66%. So I wondering which one I should go by?