Which temp/humidity level is right?

[MyLittleRedCoop]

I just had the worst. hatch. EVER.

I need to do one last batch before the season is over (since I got way less than I was hoping to hatch), but I really want to make good and sure I have this issue set before I try again, because I can't take another incubator full of dead-in-the-shell chicks.

Background - I have a Brinsea Mini that has given me near perfect hatch rates twice now (when only counting the actual fertile eggs that developed)

But I wanted to go bigger. So I got a Janoel-48. I read that it might not be accurate, so I got a mini thermometer and hydrometer to put inside with the eggs to keep things "real". According to that, the eggs were between 45-50% humidity day 1-18, then up to 75-80% for lockdown. Air cells looked good, they didn't look too low.

I put 6 of the eggs under my broody. They hatched fine. (ahem, she stepped on two killing them, but that's another issue)

11 in the J48 died in the shell. One pipped and zipped on it's own and got shrink-wrapped in the shell and needed help to hatch. Two inner pipped but died. The rest died in shell, with most of them having varying degrees of the yolk absorbed. It was heartbreaking.

So, the first thing I did was buy 2 more thermometer/hydrometers and did some comparing. And now I'm just confused.

I started by verifying the accuracy of the thermometers. The Brinsea has a glass bulb thermometer in it. As per instructions, day 1-18, half of the inner water chamber should be filled. I used this as my control measurement, as it was previously successful.

The Brinsea therm read 99* f (37.2*c).
Therm 1 read 35.2*c with 65% humidity,
Therm 2 read 95* f (35*c) and 66% humidty

Then I measured the J48. It has a digital reader with a sensor hanging inside. It showed 39.3*c with 58% humidity
Therm 1 read 35.1* c with 68% humidity
Therm 2 read 99* f (37.2* c) with 68% humidity
Therm 3 has an external sensor that I put down by where the eggs would go, approx. 1-2" lower than the J48 sensor. It read 38.1* c at 56% humidity. (I didn't use therm 3 with the brinsea, as the sensor cord would prevent the top from sealing)

So... now what?? Too many different numbers!!
Any suggestions, based on the readings, what I should set the J48 to for temp to accommodate for the inaccuracy? And what should I target as my humidity? Is it best to take the readings from down where the eggs are or above them?

Because, seriously. I can't take another incubator full of dead chicks.

 

[HEChicken]

I'd be looking at ventilation too. I've not familiar with that model but if they are developing to full term and internally pipping but dying in shell after that, it is classic lack of ventilation/oxygen. Hatching uses up a lot of oxygen so what typically happens in this case is that the first chick or two will hatch but in doing so, they use up all the available oxygen and the rest suffocate.

FYI, I had always incubated as you did, raising the humidity at the end, though never above 65%. The problem is that humid air doesn't hold as much oxygen. You can offset this somewhat by lowering the temperature a degree at the same you raise the humidity. However I recently had a situation where I was away when a turkey started to sit on a nest full of eggs. After two hatched, she abandoned the eggs so I threw the rest of them in the incubator. Not knowing how far along they were, I never raised the humidity at all. Every single one of them - including two ducks who are said to need higher humidity - hatched perfectly at the incubation humidity of 45%.

 

[MyLittleRedCoop]

Thanks for your input!
So you think stay the course, temp and humidity wise, as I did before, for day 1-18, (since a good number of them made it to day 18, with only typical cracked eggs due to shipping and a few clears as my losses) and then reduce the temp by a degree when I lock down?
I don't know how else to increase ventilation... The top has 2 small holes (about the size of a pencil) and the bottom has 4 . There are no other ventilation options. :/ One of the holes was filled with a tube that I was using to add water to the bottom tray without opening the lid.
I was worried that I had the humidty too low, since the one got stuck after pipping. But I can see what you are saying that it could get tired due to lack of oxygen.
It's a forced-air model. Do you think the fan would have caused any trouble, blowing on the eggs? I can't turn it off.
Thanks again for your help!

 

[HEChicken]

I would take out the tube since it sounds like it is blocking one of the holes, and if you can poke any more holes in to create even more ventilation, it can't hurt. I don't know where the fan is located on that model but unless it is blowing directly on the eggs, it shouldn't cause a problem and actually should aid in air exchange, helping air to be vented out holes in one side, drawing in fresh air on the other. Ideally.

99.5 is incubation temperature but after they hatch, chicks only need to be at 90-95 to be warm and happy. So by the time they are fully developed and close enough to hatching to have pipped, you can safely lower the temperature by a degree (perhaps more? I'e never tried) without harming them.

The other consideration is the accuracy of your gauges. Have you calibrated the hygrometer using the salt test? If it is off by a substantial amount, you could be incubating at 60% when you think it is at 40%.

 

[MyLittleRedCoop]

I haven't calibrated the hygrometer (Lol, I've been spelling it wrong!) But I'll do the salt test today.
Is there a way to do the same for the thermometers? I compared them to a glass one in the brinsea, but figured they were off due to location differences in the dome.
I will definitely take the tube out. In retrospect, it makes sense that blocking 1/6 of the air vents would not produce good results. (SMH!!) I only put it there, as it was recommended as a way to add water without opening the unit and getting water on the eggs. Sigh.
Thanks so much for all your great advice! I so appreciate it!

 

[HEChicken]

Sadly I haven't found a really good way to calibrate a thermometer. I prefer analog to digital as I find they are typically more accurate. I've had digital thermometers be as many as 5 degrees off from one another. Many people recommend the Brinsea Spot Check which is digital and supposedly more accurate than most, but also very pricy. A friend lost batch after batch in her Brinsea Octagon so spent the money to purchase the Spot Check, only to continue losing batches. After months, she still hadn't hatched a single chick and was getting very discouraged. It turned out both the Brinsea on-board thermometer AND the spot check were off by several degrees. As soon as she learned that and gave up on both of them, relying instead on a cheap analog, she started having successful hatches.

The way I determined that my thermometer was "likely" to be accurate was to choose a model that had 20 available at the store. Because they were packaged in clear plastic oyster packaging, I could read the temperature on them, right there in the store. 75% of them read the same, while the others were a little over or under that reading. I decided the 75% were most likely to be accurate so purchased one of those. As a further test, I brought it home and set it on the thermostat in my home (that runs the A/C and heat) for a few hours. When I checked it, it read the same as my thermostat. Assuming my thermostat reads accurately, I declared that a victory and now trust that thermometer over any other.

 

[howfunkyisurchicken]

I calibrate my thermometers by placing them in a bag with ice and water- like a slushie. The thermometer *should* go down to 32F, if it doesn't, then however far way from that temp it is, is how much its off

 

[MyLittleRedCoop]

I have a question about the salt method for the hygrometer calibration...
Testing calls for 1/2 c salt and 1/4 c water. It says the salt should look like wet sand and not dissolve.
When I added the water to the salt, I did not get a "wet sand" look, even after I stirred it. There is about 1/4" to 1/2" of water over the salt, which is settled in a layer on the bottom, beneath the water. Is this ok? Or do I only add enough water to where it's pasty/thick/wet sand - not all 1/4 cup of it?

How do you keep your digital therm parts protected from the water, howfunkyisurchicken? Or do you use a glass one?

 

[howfunkyisurchicken]

I use a glass thermometer, so I don't have to worry about it getting wet. I have a digital thermometer as well, but its pretty new so I haven't worried with calibrating it. I just calibrate my glass one and compare it to the digital.

For the hygrometer, I only use a tablespoon of salt and just enough water to make a paste Good luck!