I have my overpriced fertile eggs from ebay. I have my hovobator with a fan, and I have 3 digital thermometers all with different temperatures and no way to know if any of them are actually reading the correct temperature. I could buy another thermometer but that would just be throwing more money away. what good is another thermometer with a 4th reading going to do. How can I trust any of these thermometers. calibrating in ice water and boiling water wont work. There is no way to calibrate them. I've just had it.