Incubator humidity levels

[OldGallo]

I have read that humidity in the incubator should be at ~ 30% for the first 18 days and then increased to >50% for the last 3 days.
My incubator manual suggested > 50% for the duration. The eggs are now into the 20th day and the humidity has always been ~ 55%.
Have I killed them?
Still 3 days to go. I am pacing the corridor not knowing whether to buy cigars yet.

 

[AmyLynn2374]

I have read that humidity in the incubator should be at ~ 30% for the first 18 days and then increased to >50% for the last 3 days.
My incubator manual suggested > 50% for the duration. The eggs are now into the 20th day and the humidity has always been ~ 55%.
Have I killed them?
Still 3 days to go. I am pacing the corridor not knowing whether to buy cigars yet.

What kind of eggs are you hatching?

 

[jim2057]

You asked what eggs are you hatching. What is the best humidity for bantam eggs? Tried 40-50% and drowned the fully grown chicks. Not trying 30%, air sac looks good after 14 days but already have lost 13-14% weight. Any recommendations?

 

[OldGallo]

Hi, I have 12 Rhode Island Red eggs. I have bought these from a supplier near Melbourne (Australia). Just afraid that rough handling during transit and now perhaps high humidity may have sealed their fate. Still have 2 days to go.

 

[Yorkshire Coop]

Hi OldGallo

Have you candled during incubation to check on air sac growth. Shipped/posted eggs do tend to have a lower hatch rate due to the rough handling. For me personally 55% is too high during the first 18 days. They need to lose enough so the air sac can grow adequately for the chick to pip into.
Here is a chart for air sac growth at different stages of incubation

 

[OldGallo]

I have candled 2 of the eggs. There is an air sack, probably about the level of 14 days as shown on the diagram.
The eggs are not large and that may be the reason the sack is not as large as shown on the diagram for 18 days.
Taking the relative size of the egg into consideration it may be ok. I have not candled any more for fear of the incubator cooling down.
Fingers crossed.

 

[AmyLynn2374]

I have read that humidity in the incubator should be at ~ 30% for the first 18 days and then increased to >50% for the last 3 days.
My incubator manual suggested > 50% for the duration. The eggs are now into the 20th day and the humidity has always been ~ 55%.
Have I killed them?
Still 3 days to go. I am pacing the corridor not knowing whether to buy cigars yet.

Chicken eggs have a 21 day incubation, so if you were on day 20 yesterday, you are going on day 21 today and that is "hatch day" if they are on schedule. Did you start counting day 1 after 24 hours of incubation? Humidity needs differ for different people due to a lot of variables. Generally days 1-17 humidity is going to be somewhere between 25-55% and for hatch the recommended is at least 65%. I strive for 75%. Have you gone into lockdown? (Stopped turning the eggs, opened vents/plugs, and lockdown is the time to raise that humidity.)
We control humidity (during incubation)for the purpose of allowing the egg to loose the proper amount of moisture and there is no one "magic" number for everyone. What works for me might not work for you. Some people weigh their eggs to make sure they are loosing the the right amount, (I believe it is supposed to be roughly 13% weight loss over incubation) and others (like me) monitor the eggs air cells to make sure there is sufficient humidity. At lockdown it needs to be highered so that the chicks can hatch w/o being shrinkwrapped in the membrane.
If you candle at least on days 7 and 14 you'll know how to adjust your humidity. If your air cells are too big compared to the chart (Yorkshire beat me to it and shared the chart...lol) it means your humidity has been too low and too much moisture is escaping the egg too quick. (This can cause the membrane to shrink wrap the chicks.) In this case you up the humidity to slow/stop moisture loss. If your air cells are too small, you know your humidity is too high and not enough moisture has been lost. (This can cause the chicks to drown in the excess fluid at hatch.) In this case you would lower your humidity to increase the rate of moisture loss. By keeping an eye on both your humidity and air cells (or weight loss) you'll get a better idea of what number works for you.
I know you are past that point in this hatch, I just thought it might help to understand the humidity and something to keep in mind for possible future hatches.

 

[OldGallo]

Hi Amy, Thank you for your tips. A full 21 days in the incubator will be 8 AM tomorrow morning,( Thursday March 5th).
There is no sign of movement this morning. It is difficult to control humidity in this 'fan forced' incubator. I think trying to control it now will cause more problems. It has been fairly constant at ~ 55%.

Thanks.

 

[AmyLynn2374]

Hi Amy, Thank you for your tips. A full 21 days in the incubator will be 8 AM tomorrow morning,( Thursday March 5th).
There is no sign of movement this morning. It is difficult to control humidity in this 'fan forced' incubator. I think trying to control it now will cause more problems. It has been fairly constant at ~ 55%.

Thanks.

To be honest, I rarely see my eggs move and I am a hoverer...lol So don't let that worry you. I usually don't see the movement until they pip. 55% is low for hatch so keep an eye on them as they pip for signs of shrink wrapped due to dry membranes. I use wet sponges in my bator to help raise my humidity. (I also have a forced air. A little giant, with the fan kit installed.)
Good luck. Hope they hatch w/o problems.

 

[OldGallo]

Thanks Amy, Just placed 2 soaked sponges in the incubator. Hope for the best.
I shall now go to work but will get my wife to keep an eye on it