I have three (3) hygrometers: one that sits on top of the eggs; one that has a probe; and another that is a reptile hygrometer from the pet store. They NEVER have the same readings (or anything close). Just this morning the first one read 43%, the second was at 48% and the reptile was at 58%. Currently I am using the incubator instructions (hovabator 1588) and filling the center trough whenever the humidity gets way low (about every 2-3 days). I've had very successful hatches using the incubator instructions. But I would like to know WHICH hygrometer reading is the most "correct" since I'd like to at least have a clue what my humidity is. Any thoughts?