Give it at least 2 hours and then very faintly start tweaking, and wait 2 hrs between tweaking the temp- unless it's too hot then only wait 15 to 30 minutes. When I first started I didn't realize how darned sensitive that knob is! Seriously, you've got to move it no more than 2mm at a time! Once I'd had a few good hatches, I used a sharpy and marked my knob on one of it's ridges and marked a spot on the top of the incubator with a sharpy to line it up with. That way I'd be able to tell if I'd tweaked too far from baseline, my baseline being a happy 101F. It's better to start off slowly tweaking up from a cooler temp (in my opinion) than to burn up your embryos. I only had 4 of 10 of my very first hatch turn out, and found out it is SOOOO addictive! Good luck!