What's a safe amount of time to keep the incubator lid off?

[cupman]

I have 42 eggs in my incubator. They just passed the 5 day mark and I was considering doing the candle test in the next 2-3 days. Because I have so many eggs set I figure it will probably take me 10 minutes to candle them all. How long do hens leave the clutch when they go broody? I am considering just leaving it alone until right before lockdown but I would hate to have some exploding rotten eggs waiting for me.

What do you guys think?

 

[ChestnutRidge]

Hens will get off the nest for a half hour sometimes, especially if it's pretty warm like it would be in a house. Ten minutes would be no problem.

 

[ChestnutRidge]

In fact, check this out: http://www.brinsea.co.uk/cooling/. It will definitely help you to feel better about the time it takes to candle.