Ive changed my ideas on incubation and hatching ever since I totally screwed up a hatch a few months ago and had the best hatch ever. I always mark on my calendar when I set the eggs, what day 5 is, and what day 18 is. That way I know when to candle, and when to move to the hatcher. I had a big batch of blue rocks to hatch, and somehow I marked day 18 as being a whole week later than when it was. So as my eggs incubate, I add water periodically, maybe every 3 or 4 days. The humidity stays at around 35-45 or so. I awoke one morning to a racket in my incubator, and there was half the eggs hatched and rolling around the bator and turner. I left them all in there and they all finished hatching the next day. I didnt add any more water or open the lid. So Im now into benign neglect when it comes to hatching. My personal theory is that when the chicks hatch, the moisture inside the eggs raises the humidity by itself. Now, when I move eggs to the hatcher, I add water like I would when they were incubating. Once they start hatching, I leave them alone. I think too much humidity has killed more unhatched chicks than anything else.