Oh- and the marking of the air cells I find very helpful in letting me monitor the growth between the 3 candling periods of importance (days 7/14/18). It also helps when you mark air cells at day 18 to get an idea of where the external pip should appear and you can face that side of the egg up so you can see the pip as it happens and watch the progress.
For great candling resource I use: https://www.backyardchickens.com/t/...g-candling-pics-progression-though-incubation Great point of comparison for newbies.
For great candling resource I use: https://www.backyardchickens.com/t/...g-candling-pics-progression-though-incubation Great point of comparison for newbies.