Humidity! Y does every site say something different?

[crazychickenchick]

Ok, i'm a little confused. Every site I have visited on incubating eggs says something different about humidity. One says 45-50% another 50-55% another 60-65% for first 18 days. Is one the only right one or is it a matter of what sort of incubator you trial and error (what works for you) etc. My incubator is a 40 egg forced-air. I am worried that if i have it too hight, low etc that it will affect the hatch dramatically. My first hatch I had 16 eggs and only hatched 7. When I checked them the majority of mortality was fully formed, some with small amount of yolk sack remaining, some were through air cell but never pipped.

I have 28 eggs in this time and don't want to loose as many. Any thoughts or advice?

(by the way, i am new here. Just joined today although have been reading all your wonderful posts. This site is fantastic. Havn't felt alone though my wonderful ride on the incubation train at all!)

 

[MoonbeamQueen]

May I call you CC? I'd be curious about humidity also. I'm on day 3 of my first hatch. My hygrometer says I'm at about 70% humidity. I have no water in the bator I have both ventilation plugs out. I'm in Northern CA, so it's not like I'm in a real humid part of the country to start with. Hopefully, my post will bump you up and we can both get some answers from the experts!

 

[Poison Ivy]

I keep my humidity at 45%-50% for days 1-18 then bump it up to 65%-70% on days 19-21. Mine hatch out clean and easy. I just hatched out 17 cortunix quail a couple days ago and I have 6 black copper marans chicks running around in the hatching tray now with 6 more eggs pipped. These were shipped eggs too so I'm very happy.

 

[MoonbeamQueen]

I understand that to increase humidity I would add water to the bator, how can you decrease humidity when there is no water to begin with?

 

[Poison Ivy]

I wonder if you hygrometer is reading correctly to start with. Do you have a second one to test it by?

 

[Davaroo]

Morley Jull says 48-60% Rh throughout.
Rice and Botsford say 55%, then an increase of 5-10% after day 18.

Ill give these guys the nod. They knew more about this stuff before we were born, than we'll ever learn.

 

[crazychickenchick]

You may call me CC. I'll call you MB...lol...Wow 70% is high. That is strange that its reading that high and you have no water in. Maybe the hydrometre is reading wrong. It would defenitly be worth sticking another in there just to be sure. Thanks poisen ivy and Davaroo, will work on those basic percentages. I am in Australia and being winter at the moment the humidity is not so high here either. Mine is wavering on about 57-60% at the moment. Will try lowering it to around 50-55% and see how i go.

PS; Will having the humidity around 60% for the first couple of days affect the hatch?

 

[Davaroo]

Quote:
No.
Rh is second to temperature in criticality. It has long term effects. ie, the longer it goes on being out of whack the more it has an effect.
We control it because it affects how much moisture the egg loses. Too much over the course of the incubation and the egg will dry out. Too little and the egg will not lose enough moisture. Either extreme and the chick will not develop properly.
Consider the hen who can do nothing to control humidity - High or low humidity, she has to make the best of it. In the old days they stuck a piece of fresh sod in the broody nest, under the litter, to help add a little moisture around the eggs. But regardless, we are at the mercy of the ambient atmospheric pressure and tied to the weather.
A few points one way or another is little cause to worry. Keep it between 45 and 60 percent, or so, for the first 18 days and bump it up around 65% or a little more at the end.

 

[Three Cedars Silkies]

My first hatch I kept it 50-55% the first 18 days then up to 70%. I had several eggs that did not lose enough water and the chicks drowned. My second hatch I kept it 40-45% and then 65-70% and had a great hatch. These are the numbers I use now.

 

[Davaroo]

Quote:
Me too. When I dried it out, my hatches got better.

There is a great stickie on Dry Incubation, or the 'Modified Ambient Rh Method', as I like to call it.

Here it is:
https://www.backyardchickens.com/LC-DryIncubation.html