First "Dry hatch method" hatch....are large air cells normal?

What is your ambient humidity? That does sound large to me... I love dry hatching because it leads to air cells a third the size of the egg at lockdown--certainly not before. While I'm no expert, I would probably add some water and raise the humidity at this point. You don't want your eggs to completely dry out.

Perhaps you are working with drier conditions to begin with? So many variables!!

 

Quote: Are your eggs shipped? With my last hatch of shipped eggs a lot of the air sacs by lockdown were way to large, and those with the largest air sacs didn't hatch The first week of incubation I went with the usual 50% humidity, then I read what great results people were having with the dry incubation method and decided to try it. Where I think I went wrong was that my shipped eggs had been packed in sawdust and looked dry when they arrived, plus when eggs are shipped and shook the membranes can develope tears which makes the eggs more vulnerable to moisture loss! I was lucky and had 9 of the 16 hatch Now I have eggs on day four of incubation (I'm taking part in your June 1st hatch thread) and freaked when I candled today and saw that their air sacs are too large already After the dry hatch method didn't work well for me last time I decided to go with an in-between of 45% but after candling today I added water and brought it up to 50%. I figure I can drop it later if it looks like there is too much moisture. I am using the 1588 Hovabator also and have the center well full which gave me 45 % humidity and added about a couple ounces of water to the well next to it and it brought my humidity up to 50%. I'm afraid if you fill up another well your humidity will be too high. GOOD LUCK~ I will be watching your progress.

 

Evaporation...creating humidity...happens over surface area, not volume of water.
That means some container of some given surface shape will evaporate at exactly the same rate whether it is full, or half full.

Say you have a bucket that is ten inches across full of water...
...and you have a dinner plate ten inches across full of water...
They evaporate and create humidity in a closed space exactly the same amount/rate. Ten inches worth times pi.

A thin rag with a shot glass full of water in it will give off a tremendous amount of humidity whereas a shot glass full of water won't.

 

Understood...it was just info that sometimes to some is not too obvious. It is logical that if there is one cup of water in an incubator that adding another cup will double the humidity but it is not the volume of water that determines the humidity, but the evaporation rate which is controlled by surface size. So you can increase the humidity by taking the same cup of water and putting it in a soup plate instead of a cup.

I'm probably just a little obsessed by this as I set my first batch of eggs in my first incubator last night. I'm doing a dry hatch which I think is a misnomer as the humidity in my house right now is 97 percent...so inside the incubator has to be at least that, and probably much higher. I have to go buy a hydrometer. But...a hydrometer is a little redundant to the hen sitting in the coop on her eggs that has the same ambient humidity.

All I know is that on lockdown a large air sack is a good thing but like you I'd worry about one that big so early in the hatch...and that if there is condensation on my viewing window then that is too much humidity.

I read something about them "drowning" and have to research that. That sounds to me like the air sack is too small when they pip...but I don't know.
Will upping the humidity cause the air sack to shrink? I would not think so...it would just slow down or stop the enlargement wouldn't it?

I use the very unscientific method of judging the humidity in my house and therefore my incubator by checking how fast, or if...my dishrag and dishtowels dry. If they don't dry, it is high.

 

Oh, and all my eggs in the bator are mine. So I'm not factoring in the shipping thing.

 

Your air cells don't look too big...don't stress over it keep your humidity between 35 to 40%. What I do is fill the large water channel in mine it is a round one not square let it evaporate which means it will drop to 25% or so then fill it back up sometimes eggs are thirsty and use a lot of water sometimes not and it depends on how many eggs you have in there. I also hand turn mine so I'm checking them 3 times a day as I get close to lock down as I have some that tonite will go into lock down I'm keeping the humidity at 50% and now I will try to get it up to 65% as they hatch it rises to over 70% then as they finish it drops down to 60. Your air cell doesn't look like 1/3 of the egg if it did I would up the humidity it should be the size of a quarter @ 7-8 days @ 16 days or more the size of a 50 cent or a bit larger. Shipped eggs sometimes will have funny shaped ones but you can still go by the quarter to 50 cent piece rule.



this is what mine looks like it will hold 50+ eggs I did add windows to it so I can see what is going on but mine has a preset temp with a fan I put in a humidity/thermometer so I can check it but I've been going by the instructions that came with it and it holds it just like I've written. When it was cold I made a insulated box for it to sit in to hold the temperature but now I don't need that. I have had batches of eggs that never hatched (2) from shipped eggs but other eggs in there with them have hatched great I had 11 silkies from 14 eggs and 31 from 36, 4 from 4 etc. I started with eggs that the cost didn't break my bank account and now I don't worry too much if the eggs are good they will hatch if not oh well try again.