I just built a cooler-bator, following one of the how-to videos I saw posted on this forum. After, playing around for a half a day, I've been able to keep the temp within a 3-degree swing (99.1 through 102.4). I have a small computer fan wired in and running fine. The fan is in the upper left corner of the cooler (not the lid, but in the box), with the fan/air flow directed up. In the lid, just above the fan, I've drilled six small holes. In the bottom right corner I drilled 4 small holes, plus I've opened the drain plug (that is where my wire exit the cooler). The humidity stays at 20%. It rarely fluctuates (almost never). I've tried plugging many of the holes. Before I went to bed I plugged 4 of the 6 upper holes and all of the lower ones (except the drain plug). This morning I plugged the two remaining lid holes (but opened one of the lower holes). Still nothing. I have a shallow pan of water in the cooler, which takes up about 25% of the surface area. I also have paper towels in the pan. Since I have the temp stable, I went ahead and put in some chicken and quail eggs. But I understand the humidity will need to be higher for the final 3-4 days. Also, I built this incubator mainly to hatch out goose eggs, which need a very high humidity level. What am I doing wrong?