Originally Posted by altair
I was candling eggs a few days ago on day 18 and was noting a disparity between air cell sizes. I am currently incubating bantam, large eggs, and mid-sized eggs more on the small side. The smaller eggs seemed to have better air cells than the large eggs, who had small ones for being so late in the game. I know shell thickness and porosity have something to do with it, and the large eggs (Bielefelders) have strong shells and aren't very porous. I wonder also if their large size increases their surface-area-to-volume ratio. without doing the math to prove it.
For those that have incubated with large air cells and small at the same time, what's the best course of action? I have two incubators, I can try running one with large eggs only.
The best thing to do is not to incubate small and large eggs together. Most of mine I can incubate together without an issue, but I have extra large/jumbo green eggs that I have to incubate by themselves and run dry or they won't loose enough moisture.
I recently made the mistake of grabbing four of my green eggs to throw in with some silkies that I was having shipped. When the silkies got here they were so small compared to what I was used to and there was no way I could run my humidity as low as I normally do cause the eggs lost moisture too fast. I should not have added the other 4 I collected, but I did. 2 of them did ok, the other two did not loose enough moisture, grew too big and couldn't turn. I lost one that pipped internally at the bottom, but did not break the shell and drowned in the excess fluid. The other managed to pip all the way through and I managed to save him, but just barely because of the fluid. So, in the future the silkies will be incubated by themselves so I can run a higher humidity while the greens will be alone so I can run dry.