Sort of New to Incubation

Advertisement Purina Flock Layer


10 Years
Dec 6, 2009
I got a bator for Christmas and day 4 is complete tonight. I got a hydrometer yesterday, it was 30% and I let regulate and was 33% this morning so I added water and its settled at 39 to 40% should I add more water? It should be 50%, right? How about the last 3 days what humidity percentage?
Theres no 'right' percentage that works for everyone. It depends on the climate and your situation. Read the instructions on your incubator, and follow that. You can experiment what works best for you
with your hatches, and eventually you will find the answer for you and your situation. Humidity that is running to high can end up drowning your chicks, therefore it's best not to take a straight forward
answer on what YOUR humidity should be running. What's high for me may be low for you. When experimenting some people judge how 'correct' the humidity is by candling, and looking at the air sacs,
and others weight the eggs and look at weight loss (from the start of incubation, to lockdown, the egg should loose about 13% of it's starting weight, give or take a few %). For lockdown, higher humidity
is needed because when the egg pips and the membrane is exposed, there is a high chance for the membrane to become to dry and become shrink wrapped - if the humidity is to low.

Gypsy07's posts make alot of sense with this, so a copied and pasted one for you

Yup, humidity is a difficult one. There really is no right or wrong figure for humidity, as it depends on your bator, your eggs, and the climate where you live. What works for one person won't necessarily work for another, and what works for one person with one batch of eggs might not work again with the next batch of eggs.

It helps if you understand the purpose of humidifying your eggs, which a lot of people actually don't. Incubating eggs need to lose moisture as the embryo develops, and they do this by evaporation through the shell. So an egg won't get heavier as the embryo grows, it will actually get lighter. If you have higher humidity in your incubator, your egg will lose weight more slowly, and if you have lower humidity in your incubator, your egg will lose weight more quickly. And what you're aiming for with your humidity is to regulate it so that your egg loses the correct amount of moisture, which there IS an exact figure for.

From beginning of incubation to lockdown at day 18, a developing egg should lose approximately 13% of its starting weight. (Actually, anything from 11-15% is pretty much okay, but the closer you can get to 13% the better.) So you weigh your egg at the start and subtract 13% to get the desired end weight. Weigh another couple of times through the incubation to check how it's getting on. Increase or decrease humidity as necessary to decrease or increase the rate of weight loss, and you should be able to get your egg to the right weight fairly easily. It sounds complicated, but it's not. It's a bit of extra work, as you'll need to number and weigh your eggs and keep some notes, but it removes ALL the guesswork from humidity.

If you want to go with trial and error, you'll get there in the end. It might take you one hatch, it might take you a dozen.

If you want to nail the humidity thing first time and every time, weigh your eggs!

P.S. Some people will tell you they do well with below 20% humidity, and some will say they do well with above 60%. They're telling the truth, but they're in the minority. MOST people get good hatches with humidity that is 30-45% for the first 18 days, then 65%+ for lockdown and hatching. If you're really not sure where to start, somewhere close to there would be a good idea. :
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You will probably get many different suggestions. The eggs need to loose a certain amount of moisture during incubation. I used to incubate at around 50% humidity but have found if I keep my humidity down to around 35% (dry hatch) during incubation (day 1 through 18) and keep it around 75% during lockdown (the last 3 days) I get much better hatches, 95% to 100%.
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