Nearly 50% of my eggs did not hatch. Looks like they were nearly fully developed, but just stopped growing / or didn't hatch in the last days before hatch. 40% humidity for 18 days then 70+% for last few. Home made incubator (mini fridge) with little giant egg turner, forced air. Multiple thermometers, incubator warehouse thermostat. Set my egg-o-meter to 99.5 deg. Some chicks hatched 2 full days early!!!! All hatched before the 21st day. So I am thinking my temp is too high. Any other pointers?