I think you want the condensation so the eggs dont dry out but you dont want them soaking wet cause of mold so that is why you have to be careful about the amount of water you add. Dont take my word for it tho someone will be along to correct me if im wrong.
Opening the sealed container once weekly will prevent condensation from forming on the lid...you should see a small amount on the sides of the containers though...follow Albey's method of incubation for the proper water:substrate ratio.
I use Albey's method with an airtight lid and open it every week. With perlite, the condensation doesn't seem to gather at the top, it seems to be down at the bottom.
I am using vermiculite not perlite, so I can't use Albey's method. And I am not sure how to do the ratio thing.
Please, keep throwing out suggestions!
Thanks!
Vermiculite and Perlite are basically the same thing for our purposes, you can still follow Albey's method. I leave my lids on and remove the excess moisture daily. You can also poke a few pinholes in the lid to let some moisture escape, just don't let the substrate dry out too much.