Humidity question on incubators

[rainbowhatchery]

I built a large incubator out of a fridge in order to have a new hatch happening every week from the same incubator, cabinet style. My question is humidity. Obviously everything else stays the same but typically the last few days or week you normally jump up the humidity 20-30% above what it was in the smaller incubators. How does that work with the cabinet style where you have basically eggs at every level of incubation. You have some hatching in the bottom and new ones you just set that week on the top. Humidity has always baffled me anyway as to why you need to change it since obviously a hen sitting on eggs cant raise humidity the last week. How does anyone else with a cabinet style handle humidity levels and what levels seem to work the best for you. Thanks.

 

[Fred's Hens]

Incubate in one machine and hatch in another. That's how most of us do it. Day 19 eggs get moved to smaller, dedicated hatcher. Something easy to clean is a good goal as well.

 

[rainbowhatchery]

I dont have that option to move to another incubator I only have one. The little one I was using does not hold a temp worth a darn thats why I just built one of my own so I have to do it all in one. I know when I did alot of research there seem to be alot of people that do it this way in a cabinet style with the bottom being basically the brooder, I just wasnt sure if there was a major reason the humidity couldnt stay the same the whole time since it obviously does with a hen.

 

[WalnutHill]

You can easily make your little incubator into a good, reliable hatcher. See my thread...

https://www.backyardchickens.com/t/870591/foam-incubator-woes-and-fixes

$15 for the digital controller, the rest of the stuff was scavenged from project leftovers.

 

[rainbowhatchery]

Got both running good now