woke up to 10%humidity this morning.. day 4.

[Minky]

If they were at 10% humidity for, say 6-8 hours- what would that do to the eggs on day 3/4.
Thanks

 

[jher77]

Nothing. Just bump up your humidity a little to compensate. The final average at lockdown is what counts.

 

[ChickenCanoe]

IMHO, not a problem.
Humidity isn't a set number that must be maintained. First of all, all eggs vary greatly in porosity.
Secondly, in nature, humidity varies widely. A hen in an arid climate may experience very low humidity but then again, a thunderstorm can come along and run humidity up to 95-100%.
It is the overall weight loss during incubation that matters. About 13% throughout.

 

[jher77]

Humidity controls the weight loss.

 

[Minky]

IMHO, not a problem.
Humidity isn't a set number that must be maintained. First of all, all eggs vary greatly in porosity.
Secondly, in nature, humidity varies widely. A hen in an arid climate may experience very low humidity but then again, a thunderstorm can come along and run humidity up to 95-100%.
It is the overall weight loss during incubation that matters. About 13% throughout.

So should I have weighed my eggs before putting in? I'm interested in this- Ive never really read much about that. I see people marking air cells, but to what end? Can you explain? Can I weight them now. its day 5.

 

[Minky]

so

Humidity controls the weight loss.

if high humidity not as much weight loss? low humidity lots of weight loss?

 

[Mellowmalt]

so

if high humidity not as much weight loss? low humidity lots of weight loss?

yes that is exactly right. Temperature and air flow will also play a part in the drying but not as much as humidity.

Imagine you have a glass of water and you leave it on the kitchen counter for 3 weeks. The aim is to have the glass of water evaporate, not too fast and not too slow. If sun were to shine on it it would evaporate in less than a week. In a very humid cool place it might not lose much water at all.
If one week it loses half the water, then for the next weeks you place it somewhere really humid then it will hardly lose any water and will have gotten back on track to losing all the water by the end of week 3 again so the humidity is not crucial at any time as such but the overall average and more important the rate of transpiration as a result over the whole 3 weeks.

Day 5 is a good day to weigh them but you need jewellers scales that can measure to 0.1g or ideally 0.01g

What you do then is you work out how much your egg should be losing per day from then on.

Lets say your egg weighs 50g on day 5 (ideally you start with the original weight but day 5 is close enough).

Over the next 21 days it should lose 13% of its weight. So 13% of 50g is 6.5g weight loss.

Ok so next you divide the total weight loss the egg should achieve by 21, so 6.5/21= 0.3grams per day.

Then you either weigh some eggs daily and track their progress or weigh again in a few days time - lets say you check again on day 10, so 5 days later. In 5 days it should lose 5 x 0.3g = 1.5g

So on day 10 your 50g egg on day 5 should now weigh 50-1.5 = 48.5 grams

If the egg weighs less than this then it is losing more moisture than it should be and you need to increase humidity slightly.
If the egg weighs more than this then it has lost too little moisture and so humidity needs to be lowered slightly.

 

[ChickenCanoe]

So should I have weighed my eggs before putting in? I'm interested in this- Ive never really read much about that. I see people marking air cells, but to what end? Can you explain? Can I weight them now. its day 5.

Marking air cells is a visual way of observing weight loss. The bigger the air cell, the more weight (moisture) lost. Most people do it that way but I don't like handling them that much. I'm prone to dropping them.
I don't think that many people weigh but IMO it is the most accurate way of knowing if the eggs are experiencing proper humidity.

https://poultrykeeper.com/incubating-and-hatching-eggs/weight-loss-method-forl-incubation/

 

[Minky]

Marking air cells is a visual way of observing weight loss. The bigger the air cell, the more weight (moisture) lost. Most people do it that way but I don't like handling them that much. I'm prone to dropping them.
I don't think that many people weigh but IMO it is the most accurate way of knowing if the eggs are experiencing proper humidity.

https://poultrykeeper.com/incubating-and-hatching-eggs/weight-loss-method-forl-incubation/

thank you!

 

[Minky]

yes that is exactly right. Temperature and air flow will also play a part in the drying but not as much as humidity.

Imagine you have a glass of water and you leave it on the kitchen counter for 3 weeks. The aim is to have the glass of water evaporate, not too fast and not too slow. If sun were to shine on it it would evaporate in less than a week. In a very humid cool place it might not lose much water at all.
If one week it loses half the water, then for the next weeks you place it somewhere really humid then it will hardly lose any water and will have gotten back on track to losing all the water by the end of week 3 again so the humidity is not crucial at any time as such but the overall average and more important the rate of transpiration as a result over the whole 3 weeks.

Day 5 is a good day to weigh them but you need jewellers scales that can measure to 0.1g or ideally 0.01g

What you do then is you work out how much your egg should be losing per day from then on.

Lets say your egg weighs 50g on day 5 (ideally you start with the original weight but day 5 is close enough).

Over the next 21 days it should lose 13% of its weight. So 13% of 50g is 6.5g weight loss.

Ok so next you divide the total weight loss the egg should achieve by 21, so 6.5/21= 0.3grams per day.

Then you either weigh some eggs daily and track their progress or weigh again in a few days time - lets say you check again on day 10, so 5 days later. In 5 days it should lose 5 x 0.3g = 1.5g

So on day 10 your 50g egg on day 5 should now weigh 50-1.5 = 48.5 grams

If the egg weighs less than this then it is losing more moisture than it should be and you need to increase humidity slightly.
If the egg weighs more than this then it has lost too little moisture and so humidity needs to be lowered slightly.

Awesome. I have a scale in my kitchen like that. Will weigh a few of the large eggs and a few of the smaller eggs. Excellent info, and nice and clearly stated. Thanks again