Temperature Question I NEED HELP!!!!!!!!

[BlaineWillard]

i built a homemade incubator but i cant get my temp to stay in a close range it cuts off at 100 and comes back on at 93 is this an ok temp for hatching chicken eggs or do i need to change something and how do i changing it if i do need to. i am useing a hot water heater thermostat. i need to get this right ASAP i need to start hatching 3 dozen eggs by the weekend. thanks for looking

 

[mrslb333]

It needs to be between 99.5 for forced air and 102 for still air not sure how you could do this though