Why not open after day 18?

[IggiMom]

I keep reading that it is a bad bad sin to open the incubator after day 18--is that the right day? But I am uncertain as to why. Can someone explain this to me?

 

[GaNewChick]

The last 3 days you raise the humidity for hatching. If you open the lid, a rush of dry air sweeps in and can dry the membrane resulting in the chicks dying, it also affects the temp.

What I do is on day 18, I pull the auto turner out ~ put a sponge in under the vent hole and use a piece of tubing to add water.

Hope this helped.

 

[BigRay]

do you increase temp to make up for heat from turner motor?

Ray