So here is my story. Last year I tried to incubate some Rio Grande turkey eggs in a couple of still air older foam incubators. It was not good. I measured temps and realized the older incubators had so much fluctuation and that the temps were all over the board. So I purchased 2 new digital incubators with egg turners and fans etc. I got them all set up ( one for incubation and one for hatching) and purchased 3 medical grade probe type thermometers so that I could get accurate temps .All 3 are different brands and all read the exact same temps. When the machines were stabilized I added several eggs. The eggs were clean, at room temp prior to placement in incubator. None were over 6 days old. The room the incubators are in is stable at 65 degrees. All seemed good and the machines seemed to hold a very steady temp. 99.5 to 99.9 was the range. I was measuring temps at mid egg level. Originally I had humidity at 45 percent. The turner turns the eggs every 2 hours. And I was doing a 1/4 rotation of each egg on the turner also once a day.Yes the eggs were large end up in the turner. I watched the air sacs and they were a tad small towards hatch so I lowered the humidity a bit. At day 25 I moved the eggs to the hatcher and placed them on their sides without the turner. Got humidity up to 75 percent plus. Lowered temp down to 99 ( 98.7 to 99.). About half of the eggs pipped and died. A couple zipped and didnt finish and died. Many never even pipped. Fully developed chick just dead in the egg. Almost all the eggs have fully developed chicks in them, but I loose them all. I have had this happen with over 30 eggs so far and was able to save 2 chicks. Had to help them finish zipping. I have all the air holes open on the incubators so air should not be the issue either. I have tried to be so meticulous and precise with this and its been an epic failure. Anyone have any suggestions before I toss these incubators in the trash and give up???? So frustrating to say the least.