Humidity for day 1 through day 18

[Elana DeBolt]

What is the best humidity to keep chicken eggs on day 1 through day 18.

 

[Egghead_Jr]

I like 30ish percent RH to day 18 or 19 then up to 70% RH. 25-35% is pretty good but if on high side of that range find I need to run completely dry for few days prior to upping humidity for hatch. Hence the sometimes running dry to day 19 in attempt to grow the air cell more.

Perform a salt test on your hygrometer, they can be off by quite a bit and need calibrating.

 

[Elana DeBolt]

I like 30ish percent RH to day 18 or 19 then up to 70% RH. 25-35% is pretty good but if on high side of that range find I need to run completely dry for few days prior to upping humidity for hatch. Hence the sometimes running dry to day 19 in attempt to grow the air cell more.

Perform a salt test on your hygrometer, they can be off by quite a bit and need calibrating.

What's your normal hatch rate? Thanks for the advice, I'm going try the test.

 

[Egghead_Jr]

Sometimes high 90% but over the years I've come to count on 8 of 10 to hatch and anymore is a bonus. Depends on a lot of variables and Humidity is not one of them for me as that's a been a constant for many years now.

 

[dekel18042]

I like 30-40% during incubation and 60-70% during lockdown. My hatch rate using my own eggs was over 99%, Then I just did a batch were only two thirds hatched But some possibilities. I added eggs from my oldest hens because I liked the way they had produced over the years so that accounted for part of the problem as very few hatched, and I accidently got the humidity slightly too high in the beginning and figured I would just let it drop naturally. While I was out my husband noticed it was dropping and filled it to the brim sending the humidity through the roof for incubation. Even opening all the vents it took days for the humidity to drop. Plus I had put too many eggs in the incubator so when I laid them down for lockdown they were on top of each other. So I've learned several things not to do although I have never done them before

 

[Egghead_Jr]

Let me bee clearer why I will run completely dry sometimes. I candle the eggs around day 10 to check for any clears to toss and quick look at air cell size, make any adjustment I can if off a bit. If the air cell is still not large enough to my liking day 14 run completely dry until they are the size I want then up to 70% RH. Sometimes that will go into day 19. It's very dependent on your house humidity. Some springs the incubator only needs a shot glass sitting in it to get 28-30% and if that's the case don't have to do anything. If fumbling with container size and finally settle for something pushing 35% I'll have to run dry to catch the air cell size up.

Here's a diagram to give an idea of what I shoot for:

Nope, can't find the photo since the new fromat...google or search here for "egg air cell size by day".

 

[Chicken Chat]

I like to usually go 30-35%. The time of year, house humidity, and how full the incubator is will throw off how much water you add. My last batch hatched about 6 weeks ago so I had not turned the house air conditioner on yet, rainy spring had the house humidity around 55%, I had a dozen eggs in there and ran 100% DRY the whole 18 days and my two newly calibrated hygrometers were reading 40-45%. I couldn't get the humidity lower. I only added water at lockdown and had 11 out of that dozen hatch and they were shipped eggs. I was thrilled. It just goes to show you need to rely on your hygrometers and make sure they are calibrated and not what the owners manual says.

 

[SarahMay]

So less humidity is better it seems? First time I've done this. Should I flip the eggs every single day or is once every several days ok?
Thanks for all this input.

 

[Elana DeBolt]

So less humidity is better it seems? First time I've done this. Should I flip the eggs every single day or is once every several days ok?
Thanks for all this input.

You should flip the eggs no less then 3 times a day, i flip mine every 2 to 4 hours in the day ( i'm a night owl so around 3am is the last time i flip them until i get up which is around 11 to 12) if you don't flip the eggs 3 times a day the embryo can stick to the shell and died.

 

[Elana DeBolt]

Let me bee clearer why I will run completely dry sometimes. I candle the eggs around day 10 to check for any clears to toss and quick look at air cell size, make any adjustment I can if off a bit. If the air cell is still not large enough to my liking day 14 run completely dry until they are the size I want then up to 70% RH. Sometimes that will go into day 19. It's very dependent on your house humidity. Some springs the incubator only needs a shot glass sitting in it to get 28-30% and if that's the case don't have to do anything. If fumbling with container size and finally settle for something pushing 35% I'll have to run dry to catch the air cell size up.

Here's a diagram to give an idea of what I shoot for:

Nope, can't find the photo since the new fromat...google or search here for "egg air cell size by day".

I'm running my "Mini 7 Eggs Digital Incubator Temperature Control Chicken Duck Goose Egg Incubator Automatic Egg Incubator" dry but the RH is 50%. Is there any way I can get it down it 30% RH? Would putting a soda lid with rise in it help absorb some of the humidity?