Low Humidity Nurture Right 360

[catsndogs4us]

Just remember to keep an eye on the air cell growth so you know whether to adjust the humidity up or down. Humidity in the early days of incubation is about allowing the eggs to lose the perfect amount of water weight (11-13% by day 18 is usually optimal).

I've been hatching for a while by gauging my air cell size (without weighing) with great results but because all of the good examples of air cell growth are digital images I started working on weighing as well as marking the air cells so I can give real life examples on different sized breeds. I've only finished the bantams (Silkies) but I'll share the digital and bantam air cell growth images to hopefully give you an idea of what you should be seeing.

Good luck on your hatch! I think you'll love your Nurture Right! I just finished a hatch last night and had 94% hatch rate overall!

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Thanks so much CluckNDoodle, these charts will be incredibly helpful!

 

[SteveWin]

I'm 12 days into my first hatch with my new NR360. For the first day, humidity ranged between 35 and 45%, with the vent at about 45% open. I rolled up a bath towel and wrapped that around the unit base, just to cut down exposure to drafts and provide a bit of insulation for the water chamber (warm water evaporates better..). Since that, humidity is rock steady at 50.

I weighed each egg on a 1kg x 1g (capacity x accuracy) scale, twice, five days apart. In 5 days, 16 eggs have lost 24 g to evaporation - that's 1.5g per egg. Since the eggs started out at around 51g each, they've lost about 3% of their weight over 1/4 of their incubation, so they're on pace to lose 12-13% of their weight during the whole cycle. This is perfectly in line with something I found online, saying that 13% weight loss by evaporation is the target. (I'll find that source again and edit this to post a link.. [edit: here's one.. https://www.brinsea.com/Articles/Advice/Humidity.aspx .. here's another.. http://www.poultryhub.org/physiology/incubation/])

If the eggs were losing more weight faster, I would raise the humidity, and lower it if the eggs were retaining water. But it seems that the 50% reading on my unit (regardless of the actual "absolute" humidity value) is a good "reference" humidity to keep my eggs in line with the published evaporation rate. Ultimately, what matters is that the eggs are not losing too much or too little water. Monitoring the weight loss of the eggs is the most direct way to obtain the information to control that - and if I have to adjust my machine so it says "30%rh" to achieve the right evaporation rate, then that's what I will do.

Long story short.. I'm not yet equipped to determine the accuracy of either sensor/display on my incubator, but it is holding the values described in the manual (99.5°, 50% rh), and those values seem to be working well, at least with respect to keeping water evaporation in line with published advice. My towel "scarf" definitely helped with stability of the readings.

(To be honest, I'm barely equipped to measure the weight loss.. the 1g resolution of my current scale is too "blunt" to really evaluate weight loss per egg. (Right now it looks like "these 8 eggs lost twice as much as those 8 did (2g vs 1g..).) It's only by averaging 16 eggs of data that I have any confidence at all in my result so far. I have another scale (1000g x 0.1g, 10x more resolution, $16) arriving tomorrow - I'll repeat the weighing when it comes and again 5 days later, and use the better data to tune my humidity better..)

Finally.. because relative humidity is defined for specific temperatures, an inaccurate temperature sensor can affect the humidity reading too. If the air is really 2° warmer than the displayed value, then the same amount of moisture in the air is a lower rh (because warmer air has a higher capacity to hold moisture, so the 100% humidity "ceiling" is higher, and a given mass of water vapor per volume of air, is a smaller percentage "relative" to that higher maximum. If the unit's temp measurement is an input to calculating its rh display, then the error is compounded..

 

[Happy Helper]

I maintained humidity at 45% the first 18 days by adding 1/4 cup each morning and evening to A. It worked perfectly. Last evening was day 19 and I have had no luck getting the temp to stabilize and reach 65%. Found out something last evening, I knew that B would take a cup of water so I added a cup yesterday at noon and another cup last evening. I'll bet you can guess what happened, the water started coming out the bottom but it was still 60%. I cleaned up that mess and went to bed after I tried to drain excess water off the bottom.

The next thing I knew, my printer woke me up, the electricity had gone off and returned so of course I checked the Incubator. It had spiked to 80% and temp was 85 degrees. The temperature came back immediately and the 80% went down. This morning I found a little bantam had hatched. The little chick is running around looking for a friend. There is another pipping. I don't know what the 60% humidity will do to this hatch but we'll soon find out. I am wrapping towels around the base to see if it helps.

 

[CluckNDoodle]

I maintained humidity at 45% the first 18 days by adding 1/4 cup each morning and evening to A. It worked perfectly. Last evening was day 19 and I have had no luck getting the temp to stabilize and reach 65%. Found out something last evening, I knew that B would take a cup of water so I added a cup yesterday at noon and another cup last evening. I'll bet you can guess what happened, the water started coming out the bottom but it was still 60%. I cleaned up that mess and went to bed after I tried to drain excess water off the bottom.

The next thing I knew, my printer woke me up, the electricity had gone off and returned so of course I checked the Incubator. It had spiked to 80% and temp was 85 degrees. The temperature came back immediately and the 80% went down. This morning I found a little bantam had hatched. The little chick is running around looking for a friend. There is another pipping. I don't know what the 60% humidity will do to this hatch but we'll soon find out. I am wrapping towels around the base to see if it helps.

Was there any condensation built up on the plastic when there was a power outage? Hopefully it wasn't too long. 60% humidity should be just fine, it will spike when chicks hatch and dry off in the bator. Fingers crossed for a great hatch!

 

[Happy Helper]

Yes, there was condensation built up. I had put a cotton ball soaked in water into the incubator when I put it into shutdown. I took the cotton ball out and closed it up. The condensation dissipated quite soon. The power outage might have been three hours. It is quite unusual for us to have a power outage. I would not have known except for the printer going back on and my alarm clock being off. My little chick is lookin at me right now since the incubator is on my desk. The hatch date is tomorrow. Hope it gets some friends.
Thank you for your reply.
Helen

 

[catsndogs4us]

I'm 12 days into my first hatch with my new NR360. For the first day, humidity ranged between 35 and 45%, with the vent at about 45% open. I rolled up a bath towel and wrapped that around the unit base, just to cut down exposure to drafts and provide a bit of insulation for the water chamber (warm water evaporates better..). Since that, humidity is rock steady at 50.

I weighed each egg on a 1kg x 1g (capacity x accuracy) scale, twice, five days apart. In 5 days, 16 eggs have lost 24 g to evaporation - that's 1.5g per egg. Since the eggs started out at around 51g each, they've lost about 3% of their weight over 1/4 of their incubation, so they're on pace to lose 12-13% of their weight during the whole cycle. This is perfectly in line with something I found online, saying that 13% weight loss by evaporation is the target. (I'll find that source again and edit this to post a link..)

If the eggs were losing more weight faster, I would raise the humidity, and lower it if the eggs were retaining water. But it seems that the 50% reading on my unit (regardless of the actual "absolute" humidity value) is a good "reference" humidity to keep my eggs in line with the published evaporation rate. Ultimately, what matters is that the eggs are not losing too much or too little water. Monitoring the weight loss of the eggs is the most direct way to obtain the information to control that - and if I have to adjust my machine so it says "30%rh" to achieve the right evaporation rate, then that's what I will do.

Long story short.. I'm not yet equipped to determine the accuracy of either sensor/display on my incubator, but it is holding the values described in the manual (99.5°, 50% rh), and those values seem to be working well, at least with respect to keeping water evaporation in line with published advice. My towel "scarf" definitely helped with stability of the readings.

(To be honest, I'm barely equipped to measure the weight loss.. the 1g resolution of my current scale is too "blunt" to really evaluate weight loss per egg. (Right now it looks like "these 8 eggs lost twice as much as those 8 did (2g vs 1g..).) It's only by averaging 16 eggs of data that I have any confidence at all in my result so far. I have another scale (1000g x 0.1g, 10x more resolution, $16) arriving tomorrow - I'll repeat the weighing when it comes and again 5 days later, and use the better data to tune my humidity better..)

Finally.. because relative humidity is defined for specific temperatures, an inaccurate temperature sensor can affect the humidity reading too. If the air is really 2° warmer than the displayed value, then the same amount of moisture in the air is a lower rh (because warmer air has a higher capacity to hold moisture, so the 100% humidity "ceiling" is higher, and a given mass of water vapor per volume of air, is a smaller percentage "relative" to that higher maximum. If the unit's temp measurement is an input to calculating its rh display, then the error is compounded..

Lots of interesting information here, thanks for sharing! A towel around the base to keep the water warmer sounds like a great idea.

 

[catsndogs4us]

I maintained humidity at 45% the first 18 days by adding 1/4 cup each morning and evening to A. It worked perfectly. Last evening was day 19 and I have had no luck getting the temp to stabilize and reach 65%. Found out something last evening, I knew that B would take a cup of water so I added a cup yesterday at noon and another cup last evening. I'll bet you can guess what happened, the water started coming out the bottom but it was still 60%. I cleaned up that mess and went to bed after I tried to drain excess water off the bottom.

The next thing I knew, my printer woke me up, the electricity had gone off and returned so of course I checked the Incubator. It had spiked to 80% and temp was 85 degrees. The temperature came back immediately and the 80% went down. This morning I found a little bantam had hatched. The little chick is running around looking for a friend. There is another pipping. I don't know what the 60% humidity will do to this hatch but we'll soon find out. I am wrapping towels around the base to see if it helps.

I hope there are soon more healthy chicks to keep that bantam company .

 

[CluckNDoodle]

I do keep a towel in front of my incubators all the time but keep in mind that the small overflow holes in the bottom also offer ventilation so it's good to not block every side of the base to continue to allow for good ventilation.

 

[SteveWin]

I maintained humidity at 45% the first 18 days by adding 1/4 cup each morning and evening to A. It worked perfectly. Last evening was day 19 and I have had no luck getting the temp to stabilize and reach 65%. Found out something last evening, I knew that B would take a cup of water so I added a cup yesterday at noon and another cup last evening. I'll bet you can guess what happened, the water started coming out the bottom but it was still 60%. I cleaned up that mess and went to bed after I tried to drain excess water off the bottom.

The next thing I knew, my printer woke me up, the electricity had gone off and returned so of course I checked the Incubator. It had spiked to 80% and temp was 85 degrees. The temperature came back immediately and the 80% went down. This morning I found a little bantam had hatched. The little chick is running around looking for a friend. There is another pipping. I don't know what the 60% humidity will do to this hatch but we'll soon find out. I am wrapping towels around the base to see if it helps.

I found an online humidity calculator at https://www.rotronic.com/en-us/humi...umidite/humidity-calculator-feuchterechner-mr

I ran your numbers through it.

85°f air at 80%rh contains 10.28 gr (grains: 437.5 grains = 1 oz) of water per cubic foot. 85⁰f air is "saturated" at 12.86 gr/ft³

Air at 99.5⁰f, with 10.28 gr/ft³ water vapor, is at 58.6% rh. 99.5⁰f air is saturated at 17.53 gr/ft³. Since this temperature is our reference, the other temp's saturation point is 26.6% lower than this standard.

So, your incubator was running near (probably right at..) 60% humidity at 99.5⁰f. When the power went off, the heater stopped and the air began to cool, but the air didn't gain extra water to jump to 80%rh, the higher rh reading was relative to the 30% lower maximum for the cooler air. When heating was restored, the air had lost only about 1.5% of its water content in that period. (You didn't say what the post restoration humidity dropped TO, so I'm going off the calculation for this endpoint). ((If your car has a top speed of 175mph.. and mine's top speed is 128mph.. and we're both driving the same route at the same time, at the same speed (103mph, which is 58% of your top speed, and 80% of my top speed), which of us reaches our destination first?))

Also.. though the air around the eggs was 1.5% dryer at the end of this cycle.. the moisture content of the eggs themselves, and of the air in the air cells, didnt fluctuate as much, due to the "diffusion coefficient" of eggshell, the fact that water evaporates from the outside surface of the shell, and replacement water must then migrate through the shell thickness before it can evaporate.. and these rates (evap and migration) are proportional to the humidity and temperature differences from inside to outside the shell. So, fluctuations of the egg interior environment, lag those of the incubator air, and are dampened by the shell and membranes..

So, I think you have nothing to worry about here, your chicklets should be fine. I hope so, anyway..

 

[Happy Helper]

Thanks SteveWin, my 84 year old brain can't process all that but I definitely enjoyed your explanation. Seems that all is fine here, they are busy hatching and the little one from yesterday has about 7 or 8 more friends.

I do a lot of browsing on this website and I have learned a lot. If I have a question, there is always an answer coming promptly. As far as this Nurture Right goes, I am completely happy with it. The temperature has been consistent all through this hatch and I guess my problems with the humidity is miniscule.