I got a Hova Bator second hand, seller said it was used just once. Thankfully I have been testing it before any eggs have arrived. Im a newbie but its been awful trying to get this thing set to correct temp. We will be getting a half dozen Silkie eggs in a couple weeks. Anyways is the Wafer supposed to spin when I turn knob? I will adjust down or up and the fluctuations are about 5-10 degrees. Maybe im turning too much or im thinking maybe I need a new Wafer? Should I turn until the light goes off or?? I think I have a good understading of how it expands and eveything looks in good condition. I also noticed that the temp drops dramatically when I open. Seems like if I turn eggs by hand and the temps fluxuate like that 3x a day that could be bad. And last thing is it worth it to get a fan? I dont want to shell out all the money for a new wafer, turner and fan if the core of it wont even hold temp! Advice?