Thank you so much for explaining the intricacies, it is officially day 21 in 2 hours.
I turned temp down from 37.5 to 37, on Sunday, 3 days ago, (day after I stopped turning)
I have 1 pipped shell, no sounds.
I could up the temp again, if that would be better for them to 37.5(I was following Brinsea incubator suggestions.) as don't want to slow things down unnecessarily.
Other thing is there are 2 types of egg. The light Sussex ( big eggs) have very variable sized airsacs. Some are a bit small looking.
The cream legbar are looking a lot more uniform. Nice big airsacs The overall weight loss was averaging out perfect on day 17, guess they're all individuals.
This is crazy, I was so offhand when I was expecting my human babies, weird how this is such a nail biter!