YEah I sealed mine up completely, with the P&S, then put my lids on.

I have been airing it out once a week during incubation, now that they are getting closer to hatching and producing their own heat, Im airing out once a day. After they start pipping I plan on setting them up on wet paper towels so they can crawl out onto that.

I used 3 layers of the light "diffuser" grating. I then filled the tubs up with water about halfway up the grates. i had to do it like this because the bottoms of my tubs were shaped a little funny. I do feel better knowing that my eggs are further up off the water though too.