I see many posts where people get temp spikes and fan the bator a bit too cool it down.... I think a problem with doing that is that the internal temps of eggs do not cool down that quickly and take some time. By cooling the incubator down quickly like this, it generally will drop its temperature below the low thresh-hold and immediately re-start the heating element to raise the temp due the bators temp loss. Since the heating element/lamp kicks on for a longer period now to raise the temp to the desired degree, the eggs are actually being exposed to "more" heat than if the temps were gradually lowered using the thermostat adjustment alone(possibly raising internal temps even more before dropping). By just lowering the adjustment and not losing too much temperature all at once, the eggs will gradually lower their internal temps in a short period of time and not be exposed to additional instant heat caused by opening the bator and cooling it down too much , too fast. Just a thought as to why some problems may occur. Internal temps may actually rise even more prior to cooling down if too much heat in the bator is lost instantly, thus doing more harm than good. Just a thought.... Happy Hatching!