Low hatching temp for large eggs?

[LaurenRitz]

I have the same incubator and I've had good success with it. I have a second thermometer inside that says the temp is (now) 99.5. Or rather, the red line hovers just a hair below 100.

Other than unfertilized eggs, my hatch rate is very high with just set and forget. This time I moved it because the afternoon sun was driving the temperature up, and I wanted the space in the sun for plants.

I just chose the wrong spot. It's now in another area of the house, with no sun, no drafts, and a blanket around it. Egg temperatures have risen to more reasonable levels since I measured this morning.

 

[MysteryChicken]

This test has been informative. Apparently my incubator doesn't hold temperature as well as I assumed. It goes up and down considerably with the ambient, and since the back of the incubator was against an outside wall that side is always cooler. The center is also warmer, and that's where the built in thermometer is. This morning some temperatures were as low as 92 against that back wall.

I moved it to a different location where the temps are more stable, but I may need to re-run this test at some other time. At this point, with the primary variable fluctuating so wildly, the conclusion would have to be rock solid for me to accept it.

1) moved the incubator
2) put a blanket over it
3) We'll see.

If I have a cold spot I put a paper towel over the lid in that area to help keep the draft off of it. I found doing this also help regulate the temp as well.

 

[McChooky]

This test has been informative. Apparently my incubator doesn't hold temperature as well as I assumed. It goes up and down considerably with the ambient, and since the back of the incubator was against an outside wall that side is always cooler. The center is also warmer, and that's where the built in thermometer is. This morning some temperatures were as low as 92 against that back wall.

I moved it to a different location where the temps are more stable, but I may need to re-run this test at some other time. At this point, with the primary variable fluctuating so wildly, the conclusion would have to be rock solid for me to accept it.

1) moved the incubator
2) put a blanket over it
3) We'll see.

When I gave my broody hen 4 welsummer and 4 leghorn eggs last fall only one of my welsummer eggs hatched.I'm not sure how well they'll do using the dry hatch method but I have 4 in a diy incubator

 

[McChooky]

It a positive affect. I do it for all sized eggs, including duck, & goose.

I'm hatching chicks in a diy incubator and I've turned them every day
(but not at the same time or the same intervals) I candled them on day 10 and all but 2 were viable and had veins. (one was clear and one started but died) No blood rings. I'm using the dry hatch method (leghorns and welsummer eggs)

 

[LaurenRitz]

I always do dry hatch. It just works better for me. I have far fewer that die after lockdown.

 

[MysteryChicken]

I'm hatching chicks in a diy incubator and I've turned them every day
(but not at the same time or the same intervals) I candled them on day 10 and all but 2 were viable and had veins. (one was clear and one started but died) No blood rings. I'm using the dry hatch method (leghorns and welsummer eggs)

I use the Wet Bulb method. 35% - 45% Humidity for the first 18 days, then I boost it to 55% - 65% Humidity.

 

[MysteryChicken]

I always do dry hatch. It just works better for me. I have far fewer that die after lockdown.

I've always had good luck with the wet bulb method. One important thing that must also be monitored is the in-house temperature, & humidity, cuz that also shifts the conditions inside the incubator. Of course the normal fluctuations won't hurt anything though.

 

[LaurenRitz]

I'm going to discontinue this test. I candled the eggs and the development is all over the place. Those temperature swings did a number on the eggs.

I'll probably restart at another point, under more controlled conditions.

 

[McChooky]

Edit:
I did a google search on the effects of C02 on hatching eggs in an incubator after burning some fried chicken on the stove last week
(it smoked up the house) I'm sure I'm not the only person this has happened to but it doesn't make me feel better to know it may have killed my chicks. I hope this article helps someone else as much as it did me.I never realized how important Co2 is in the different stages and development of the chicks.Thanks!
https://www.poultryhatch.com/2025/12/carbon-dioxide-levels-egg-development-hatching.html