I just finished hatching some eggs in 2 hova-bators with fans and wafer thermostats. I had automatic turners in them. Out of a total of 90 eggs I got 36 to hatch. I had a medical digital thermometer (acccurate to .2 degree) in a zip lock bag in the center. I checked the temperature and humidity 3 times a day, always when the heating element indicator light was off and temperature was in 100 to 100.5 range. They started hathing 3 days early, so I assume temperature was high, I know 99.5 is often recommended. Humidity was normally 50 to 55% except when they started to hatch and I planned to go into lockdown I upped it to about 65+%. Is the center of the incubator the best place to read the temperature? I figured so since the thermostat was there. I think fertility of the eggs should be good as someone hatched about 80% on eggs they got from me.