When do i put eggs into the incubator?

[Indianrunner123]

I have 11 duck eggs (both indian runner and call duck) sitting ready to go into the incubator. However this will not fill the incubator. The ducks are continueing to lay each day and so i was going to wait until i had enough eggs to fill the incubator before turning it on.
Although i have heard that after 7 days something happens to the air cell meaning that there is an unlikely chance of the bird hatching. Also i have heard that eggs cannot be added as the humidity is efffected.

Could someone please advise me on what to do and how long eggs can sit before being incubated. Many many thanks!!!

 

[Indianrunner123]

 

[chonsey]

Check in the learning center. I had mine in the refrigerator for 5 days, but manually moved the egg carton on an angle to the left, flat, then the right. They all hatched. My Brahmas had just started laying and I was afraid to store them any longer. Heard you have a better chance of getting pullets if the eggs get @40 deg. So I tried it. They recently hatched so I'm still waiting to see how many pullets vs Roo's.