Interestingly there are tons of variables.. including the color of your eggs and how high or low your humidity was during incubation.
But also like another poster mentioned perhaps even how many eggs you have inside what sized bator.. more eggs produce more humidity once they start pipping.. sometimes leading to a completely fogged up and dripping bator (not desirable). Condensation (dripping) can cause drowning to pipped chicks.
I'm gonna recommend 60% humidity for hatch but also provide a link to my favorite hatching resource.. (hatching humidity is on page 43)..
https://www.hubbardbreeders.com/media/incubation_guideen__053407700_1525_26062017.pdf
Happy hatching!
