I kept my humidity between 35-45% the whole 18 days it even fell to 25% a few times but it didn't bother me. day 19 I added a wet sponge and it jumped to 65% which is where I pretty much kept it and a bunch started hatching out Tues/Wed. I noticed though it wasn't enough humidity because it was taking a long time to hatch out after pipping-the membrane was really gluing to them and I had to help a few out after 24 hours-I still have 15 silkie eggs left to go-I have 2 so far they are beautiful!!!