Persistant shrink-wrapping problem

[Aziara]

I have done 4 hatches so far in my incubator, and this problem occurs in all hatches, to about 25-50% of the hatch. It has occurred with chicks from several breeds, and also to a Chinese painted quail chick, so I know it isn't a genetic issue.
The incubator is a little giant still air. Temperature is set to 101.5 degrees.
I turn the eggs 3-4 times per day up 'til day 18. (day 13 for the quail)
Humidity is 40-45% the first 18 days (I cannot get it any lower, I have it sitting next to my dehumidifier as it is) and 70-75% after removing the turner.

What happens is that the chick will pip a tiny hole big enough to breath through.... and nothing else. I usually attempt to help after the 24 hour mark. At this point, the chick is entirely shrink-wrapped, with blood trapped in the inner membrane as it dried. I wet the membrane every 10 minutes or so, and remove membrane that no longer has blood in it, though this is often difficult to tell and there's usually a few drops of blood lost. It's a long, tedious, nerve-wracking process. After it's all done, I apply some iodine to the navel stump, as I lost several of my first hatch to infections of the navel after helping them hatch.

The chicks are usually quite lethargic at first, but perk up after a few hours. By day two, it's hard to tell who had trouble, and who hatched naturally.

Is 70-75% humidity not high enough? Do y'all think my hydrometer is busted? I would rather not have to interfere, but I'm not about to let a perfectly healthy, 'lazy' chick die in the shell.

 

[formerchickenlass]

That's plenty high. I hatch my eggs at 65%, open the incubator constantly and have no problems.

Have you noticed the shrink wrapped chicks coming from all areas of the incubator or is it localized to a particular spot in the incubator?

It wouldn't be crazy to get another hygrometer to double check the humidity.

I believe humidity too low during the incubation prior to lockdown can also cause shrink wrapping.

 

[Aziara]

They don't seem localized, at least, I haven't noticed that they are. I'm planning to upgrade my incubator with a fan and turner after my current hatch, so if it is a certain spot, hopefully that will fix the issue.
I do know of a local guy who has a forced air that he runs at 50-55% humidity prior to lockdown. That always sounded too high, but I may have to try it. I wouldn't have to fight so hard to keep it down, at least. 50% or higher is the natural humidity where I live

A cheap hygrometer is certainly going to be on my list, just to be sure the readout is correct.

 

[WVduckchick]

Testing a hygrometer is easy. Google for "salt test hygrometer". Even if yours is off, the test will tell you how far it is off, and you can adjust accordingly.

But basically, if you add enough water/sponges/etc. to cause just the first hint of condensation on a window, it should be fine. Major condensation is too high.

Another consideration - ventilation. Do you keep all the vents open all the time? Mine are always wide open, but many folks recommend they be partially closed in the beginning, but fully open for hatch time. Air exchange is extremely important, and often overlooked.