Air tight incubator?

[sho220]

For the past few years I have used an incubator that had small holes for air exchange with good success.

This year I have a new incubator that is pretty much air tight. The only oxygen getting in would be from me opening the incubator periodically.

Is it essential for there to be places for oxygen to enter the incubator? Or is opening it periodically enough?

I would think there would need to be at least some air exchange, but maybe just opening it every few days would be enough? What kind of 'bator is it?

Wish I could be more help...