Are my eggs losing enough weight?

[saving grace]

Hello.

This is my first ever attempt at incubating. I'm on day 7 and 39 of 52 eggs are fertilized and growing! I'm super excited.

I'm using a hova bator and it's been working great for me. I'm going the dry incubation method, since without adding water my humidity was already 40%. I weighed the eggs yesterday and they don't seem to be losing enough weight. What I read is that by day 6 they should have lost about 4 grams, but most of mine have only lost about 2 grams, some even less.

My eggs have very thick shells, and I'm incubating quite the mix (Orpington, Andalusian, EEs, Australorp).

So I pulled out one of the red plugs to see if that helped dropped the humidity, and now it's at about 32%.

My hygrometer has been salt tested, btw.

I'm not sure if perhaps my scale isn't the most trustworthy. It keeps fluctuating between numbers if I touch it the tiny bit. Annoying.

When I candle them the air sac looks pretty much like the photos say it's supposed to at day 7, but maybe a little smaller?

Am I being too paranoid? Could the humidity need to be even lower?

Thanks in advance!

 

[2ndTink]

I tried weighing them on my first hatch but realized my scale wasn't accurate enough so went with just the visual size of the aircell and I haven't had issues just based on watching the size.

 

[ChickenCanoe]

Weight loss is about porosity of the egg, time, ambient humidity, elevation and temperature. Egg color can have an effect on porosity depending on how pigment is applied or more importantly what chemical pigments are involved and when they are applied to the shell. Most pigments creating a brown egg are applied after the shell is fully formed, so in theory, that could cover some porosity. The blue pigment is applied throughout the process of shell formation as is some of the reddish maroon egg breeds.
It is really hard to determine the porosity of eggs by observation alone. Read that as impossible. While thick shells tend to be less porous, even a thick shell can be very porous. There is virtually no water being lost through the solid portions of calcium carbonate. Pores are actually microscopic.
With all that said, knowing the humidity in the incubator is less important unless one incubates the same eggs from the same strain of the same breed, same birds laid at the same elevation over time and keeping copious notes.
So, I maintain the only technique absolutely guaranteed to tell you how much weight is lost is by weighing the eggs, at collection, at setting and periodically throughout incubation. I usually do so at day 6 or 7, and again at day 14.
To a less accurate degree, candling.
I do candle but the reasons I don't like candling is handling in order to candle is an opportunity for accidents and remembering to wash and dry hands because of possibly introducing bacteria. To save time, you can weigh an entire rack of eggs at a time. It won't detect individual variances but from experience, there is a small percentage of eggs in a setting that will deviate to a great degree from the average and then what are you going to do about it. You aren't going to change humidity for the one egg. For individual eggs, other strategies are necessary.
ETA
Reading @2ndTink answer, I understand the necessity for scale accuracy. I have found that small pocket gram scales to be more repeatable and accurate than some of the kitchen scales I've used.
The repeatability is more important than accuracy in this case because a scale could be off by 10% but if it is repeatable, it is off by 10% every time. That is good enough for determining weight loss. We don't need to know the number of grams lost, we need to know the percentage lost. I've bought nice kitchen scales from places like target which were junk. Each time an egg was put on the scale in rapid succession, gave a different weight, sometimes widely disparate readings. Useless for our purposes. I believe the reason is, given a scale design, an egg is too light for accurate weight. Therefor the pocket gram scale is (pardon the pun) scaled for this weight range.
I found a fantastic, extremely accurate and repeatable baker's scale. Being a platform scale, you can weigh whole trays of eggs at once but sensitive enough to get accuracy on a single egg.
For serious candlers, I highly recommend the My Weigh KD-8000 from Old Will Knott Scales.
It is good for from 1 gram to 8,000 grams.
I bought a 10-gram calibration weight with it. I highly recommend both bought together.
With all the discussion of candling I see on here, there must be enough serious hatchers that would solve a lot of their problems with this scale.

https://www.oldwillknottscales.com/my-weigh-kd8000.html

https://www.oldwillknottscales.com/calibration-weights-sets.html

 

[saving grace]

Weight loss is about porosity of the egg, time, ambient humidity, elevation and temperature. Egg color can have an effect on porosity depending on how pigment is applied or more importantly what chemical pigments are involved and when they are applied to the shell. Most pigments creating a brown egg are applied after the shell is fully formed, so in theory, that could cover some porosity. The blue pigment is applied throughout the process of shell formation as is some of the reddish maroon egg breeds.
It is really hard to determine the porosity of eggs by observation alone. Read that as impossible. While thick shells tend to be less porous, even a thick shell can be very porous. There is virtually no water being lost through the solid portions of calcium carbonate. Pores are actually microscopic.
With all that said, knowing the humidity in the incubator is less important unless one incubates the same eggs from the same strain of the same breed, same birds laid at the same elevation over time and keeping copious notes.
So, I maintain the only technique absolutely guaranteed to tell you how much weight is lost is by weighing the eggs, at collection, at setting and periodically throughout incubation. I usually do so at day 6 or 7, and again at day 14.
To a less accurate degree, candling.
I do candle but the reasons I don't like candling is handling in order to candle is an opportunity for accidents and remembering to wash and dry hands because of possibly introducing bacteria. To save time, you can weigh an entire rack of eggs at a time. It won't detect individual variances but from experience, there is a small percentage of eggs in a setting that will deviate to a great degree from the average and then what are you going to do about it. You aren't going to change humidity for the one egg. For individual eggs, other strategies are necessary.
ETA
Reading @2ndTink answer, I understand the necessity for scale accuracy. I have found that small pocket gram scales to be more repeatable and accurate than some of the kitchen scales I've used.
The repeatability is more important than accuracy in this case because a scale could be off by 10% but if it is repeatable, it is off by 10% every time. That is good enough for determining weight loss. We don't need to know the number of grams lost, we need to know the percentage lost. I've bought nice kitchen scales from places like target which were junk. Each time an egg was put on the scale in rapid succession, gave a different weight, sometimes widely disparate readings. Useless for our purposes. I believe the reason is, given a scale design, an egg is too light for accurate weight. Therefor the pocket gram scale is (pardon the pun) scaled for this weight range.
I found a fantastic, extremely accurate and repeatable baker's scale. Being a platform scale, you can weigh whole trays of eggs at once but sensitive enough to get accuracy on a single egg.
For serious candlers, I highly recommend the My Weigh KD-8000 from Old Will Knott Scales.
It is good for from 1 gram to 8,000 grams.
I bought a 10-gram calibration weight with it. I highly recommend both bought together.
With all the discussion of candling I see on here, there must be enough serious hatchers that would solve a lot of their problems with this scale.

https://www.oldwillknottscales.com/my-weigh-kd8000.html

https://www.oldwillknottscales.com/calibration-weights-sets.html

Do you think I should I invest in a pocket scale, then?

And if I wait till day 14 to weigh them again, what happens if they still haven't lost enough weight?

 

[ChickenCanoe]

Did you already adjust humidity based on your belief they haven't lost enough weight?
After adjusting humidity, it takes at least a couple days to see an appreciable change in weight loss.
I would definitely move to weighing for accuracy. I used a couple inexpensive pocket gram scales for years till I needed to weigh trays of eggs rather than individual eggs. I still weighed random individuals but it depended on how many I was cooking at the same time.

 

[saving grace]

Did you already adjust humidity based on your belief they haven't lost enough weight?
After adjusting humidity, it takes at least a couple days to see an appreciable change in weight loss.
I would definitely move to weighing for accuracy. I used a couple inexpensive pocket gram scales for years till I needed to weigh trays of eggs rather than individual eggs. I still weighed random individuals but it depended on how many I was cooking at the same time.

Yes, I lowered the humidity from 40% to 33%.

I have already been weighing, but maybe I'll buy a pocket scale so I can get more accurate results.

When I weigh them in a couple days I'll update this thread!

 

[ChickenCanoe]

Yes, I lowered the humidity from 40% to 33%.

I have already been weighing, but maybe I'll buy a pocket scale so I can get more accurate results.

When I weigh them in a couple days I'll update this thread!

If one knows weight loss has been insufficient, it is important to make significant changes in RH. Just dry it out as much as possible. Humidity isn't a set number. By that, I refer back to natural incubation. A hen doesn't have a hygrometer and she can't control weather. She has to make do. She will not only adjust time on the nest due to temperature, she may even do so related to RH, because she could be sitting on eggs during a thunderstorm or a drought/heat spell in which case it can range from high 90s nearing 100% down to a humidity of 10 or 20%.

 

[saving grace]

If one knows weight loss has been insufficient, it is important to make significant changes in RH. Just dry it out as much as possible. Humidity isn't a set number. By that, I refer back to natural incubation. A hen doesn't have a hygrometer and she can't control weather. She has to make do. She will not only adjust time on the nest due to temperature, she may even do so related to RH, because she could be sitting on eggs during a thunderstorm or a drought/heat spell in which case it can range from high 90s nearing 100% down to a humidity of 10 or 20%.

Good to know!

I've been running a dehumidifier and I added some rice into the incubator. We're having a rainy spring here, so it's a fight to keep it down. It's at 32% currently, and if they're still not losing enough weight when I weigh them tomorrow I'll have to brainstorm what to do next.

 

[saving grace]

So I weighed them again today and it seems that about ¾ are on track for weight loss now, but a few are still lagging behind. I'm not going to worry too much about it and just keep monitoring the aircells.

Keeping the humidity at around 30% now.

 

[Debbie292d]

So I weighed them again today and it seems that about ¾ are on track for weight loss now, but a few are still lagging behind. I'm not going to worry too much about it and just keep monitoring the aircells.

Keeping the humidity at around 30% now.

I incubate a lot and have never been one to care much about air cells. I've always just done the same old thing every single time and have great hatch rates on my own, nearly 100%, and not-so-great hatch rates on shipped eggs; happy if I get 1/3. But that's the nature of that beast lol. I always keep mine at 35/40% until lockdown, then to 70%.

That said, I've weighed eggs in the past just to see, but mostly use it to divide hamburger family packs on my digital postage scale. I bought it over a decade ago and they don't have that one anymore. It looks about like this one, which is on sale half off.