chicken eggs

I’m not going to give recommendations on exactly what humidity levels you should use. Different ones work for different ones of us. I will comment that your choice is reasonable for most of us.

You raise the humidity after 18 days. There is nothing magic about the 21 days as far as eggs hatching. There are a lot of different things that can affect when an egg actually hatches, humidity, heredity, how and how long you store them before they start, and I’m sure several other things. The big one is average incubating temperature. If your incubator is running a little warm, they can be early. I’ve had eggs pipping when I went into lockdown after 18 days. Those eggs still hatched. If your incubator is running a little cooler than perfect, they can be a few days late.

Even after adjusting my incubator temperature to pretty close to right, in my last hatch I had one egg pip about a day and a half early and it had hatched a full day early. I could not even see a pip on any of the other eggs then, but activity soon started. I wound up with 18 chicks, most hatched a little before 21 days but a very few just after. I have no idea why that one egg hatched so early compared to the others, but this type of stuff happens a lot. Its one reason hatch time can be stressful.

The big reason to raise the humidity after 18 days is to try to have the humidity up when they pip. Even with experience with your incubator you don’t always know when that first one will start. It’s possible for the membrane on the inside of the egg to shrink around the chick and prevent it from hatching if it dries out. Just because it is possible does not mean it happens each and every time. It doesn’t always happen but it can. So a reasonable safeguard is to have the humidity up before they pip and don’t open the incubator until the hatch is over if you can manage that.

There are other reasons to up the humidity and stop turning the eggs but the risk of shrink-wrapping is a big one. E ven when I had eggs pipping when I opened the incubator to go into lockdown, practically all of those eggs still hatched.

 

Some people believe in dry hatch, then just add sponges day 18, I am hatching indoors, didn't completely dry hatch (wood stove in my house.) I had put 1/2 cup water in every other night or so, then checked my air cell compared it to what I have seen on computer. If the air cell is small you have too much water, if it is too big not enough water. if you go by this on day seven, and day 14 you have a few days to correct it before lock down at day 18. If on day 18 the air cell is up too high and not slanted slightly, your chick has too much water in egg, or even if your calender says day 18 you might be behind. If you put it into lock down it could drown, so I would keep it dry for a bit, I have too hatchers going one for lock down if the egg is ready and a dryer one for eggs that are draggy.

 

Your welcome to my incubating notes https://www.backyardchickens.com/a/hatching-eggs-101 there is a section on humitidy. Good luck! What are you going to hatch?