when you set it up you can fill a few 20 oz.pop bottles with water and put them in side the bator and plug it up and let the temp get stable. Then you can adjust you temp. when you get it stable (4 to 8 hours later)pull the bottles out and put you eggs in BUT DON"T TOUCH THAT TEMP CONTROL AGAIN. because it will drop in temp for a few hours before it get back normal and if you mess with it you will fry you eggs.