I've never heard any of that about using a glass of water. That doesn't seem right to me at all. Thermometers are to measure the air temp. At egg level the goal is 99.5. If putting it in water is making the air temp 106 it would fry the eggsI just got a hygrometer at walmart that has a probe you can dangle through the vent at egg level. Its about $13 I think and works very well.![]()
A lot of people say to use a baby food jar full of water and check it with a oral thermometer. This temp should represent the temp inside an egg. Some use a thing called a water wiggler to determine temp inside of egg.