Lockdown question

[Naser]

Is it true that after the first chick hatches you don't open the incubator for 48 hours, or do you take the chicks out as they fluff?.
I watched a guy in youtube saying if you take chicks out humidity will drop and other chicks may fail to hatch and die

 

[ChickenCanoe]

It depends on the incubator/hatcher but in general, you want to keep it closed till all chicks hatch - hence the term 'lockdown'.
Once pipping begins, it is imperative to keep humidity up. Opening the incubator can cause an instant drop in humidity. The inner membrane needs to stay soft and moist for a chick to break free. When it dries out it hardens and shrinks. The chick can't move then and will almost always fail.

I said it depends on the incubator because there are options. You can run a humidifier in a small space like a closet where the incubator is. I built a cabinet incubator with a separate hatcher drawer in the bottom. The air for the hatcher surrounds the incubator and constantly moves past the eggs, pulled by a bank of fans up past a heat element on one side of the incubator, across a water reservoir on top, then down past another heat element on the other side, over another water reservoir as it moves across the eggs again. It is also in the cellar where it is more humid but because there is a volume of humidified air 7 times the volume of the hatcher itself continuing to move across the eggs, It is possible to pull a couple chicks out quickly with less chance of casualties.
The best bet is to set all eggs of the same size and age at the same time to prevent a staggered or protracted hatch.