Problems with humidity levels when incubating.


In the Brooder
6 Years
Sep 19, 2013
Hi first post, however found these forums to be very helpful.

I am currently trying to incubate my first batch of chickens using a second hand rCom 20 incubator.
the device is only reaching 30% humidity even though have programmed it to reach 45%.

i keep adding moist sponges and it brings the hv to 41--43

The temperature is at a constant 37.5 C

Will the fluctuating humidity levels effect the birds or is 30% ok for the first 19days

Im a real newbie at this and any hints or tips would be greatly appreciated.

DAN and Nikki

PS. i think the heating element is broken/limescaled thats why it isnt reaching apropiate levels.
eggs have been in for 13 hours when this is posted cheers
They'll be fine at 30% for the first 18 days. When you up the humidity for lockdown, tryto using a shallow dish with the sponge sticking partway out. Or, if you have a humidifier, run it near the incubator. Good luck :)
Thanks for the reply.

so is it better to leave at 30% than keep opening to replaces sponges and such to raise it to the ideal 45%?

also I have a row free in the incubator so that's where i have placed a sponge is that suitable? i was also thinking would a shammy leather be better than a sponge as it can hold more water?


So glad i joined BYC for life!
Sorry to leave you hanging!

I would just leave it at 30% until day 18. I do all of my hatches like this now (a dry hatch, I keep the humidity between 25-30% if I can get it that low). Then I bump it up to 55-60% for lockdown. I've had MUCH better hatch rates since I started dry hatching.
When you go to raise the humidity, try using a wider bowl. The more water surface you have exposed, the easier it is to make it humid. Also, remember that if your bator has removable plugs, you can put them back in the help regulate humidity.

Do you have an extra thermometer and hygrometer in there? If not, its a good idea to get extras. I never trust just one, or my bator, so I have 2 thermometers and 2 hygrometers to give multiple readings. Remember to calibrate them each time you incubate as well. Good luck!
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any ideas anyone?
The climate and even the daily weather were you are can and will affect the humidity in your incubator. The humidity levels you read about are optimal levels. Temperatures on the other hand are much more critical and there is no room (well very little room) for error.

When humidity becomes critical is at pipping. First the chick must be able to position itself where its beak can pierce the air cell membrane at the big end of the egg so that the chick can fill its lungs with air for the first time. Then the chicks must rotate itself inside the egg shell, perforating or cutting the shell in half with its egg tooth as it goes. If the membrane is dry and leathery the chick will become stuck like a postage stamp inside the shell. Then the chick will be unable to move and it will die from exhaustion or suffocate. I guess another way to look at humidity is to think of it like the 'water' that breaks when child birth begins to help ease the baby's entry into the world.
Ok thanks ver much for all the help i am using a sponge re-wetting every 12 hours so it raises to 45% then drops to around 38% then repeat.

temp is always at a constant 37.5 c

When it is day 19 i will just have to add a bigger sponge or figure something out.


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