Everyone hatch or do you have stragglers?? How long do you give them??
We run a wood stove and the %RH has been mostly at 19 in the incubator, so I have added a little water, and then it has been closer to my summer numbers of 25-30 until the water is gone, which I let it.. I was afraid I might dry out these eggs with the dry air. I can hang items for drying in the house and whoosh, they are dry!!
I candle to look at the air cell size and yes I usually dry incubate too.
I do see a difference in air cell development based on the number of eggs I stuff into the incubator. With a lot of eggs that is a lot of moisture, and how open the vents are, and the fan . . . . many factors play into a good aircell development.
I just sold a few EE pullets to a nice home. I'm a bit sad as I sold one of my favorites. SO hard to hatch them, raise them and then sell them. MUCH easier to sell hatching eggs!!