Most people call Day 18 = lockdown. Up the humidity & stop turning eggs. (Pretend the incubator is locked. Don't open it or you'll loose that precious humidity.)Ok thanks. I go to 70 percent then and remove turning trays,, right? My dad and I hatched when I was a teen. Dad died 3 yrs ago..he knew so much! So im trying to find info on the net now,, its SO conflicting..one site said 60 on humidity was perfect and 100 deg...another said 45 to 50,, let alone the different opinions on lockdown numbers, lol
The temp depends on type of incubator (still air or circulated air =has fan) While the humidity changes on day 18, the temp should stay the same. Some people use a technique to reduce the temp by .5 degree as the eggs near hatch, but learning the basics is important before making adjustments.
There's a BYC article hatching eggs 101 that has a lot of great info. https://www.backyardchickens.com/a/hatching-eggs-101