You need to put some plastic wrap or the Glad Press and Seal wrap under that lid. The first time I did this, I lost an 11 egg clutch because I thought the lid alone would hold in humidity. It doesn't, not near enough anyway.

I wrap my lid with a couple of layers of plastic wrap, and not too tightly, then put the lid back on. The plastic wrap forms a really good seal and keep humidity high. I just open the tub for a few minutes once a week, and candle the eggs at that time. I've had 5 good clutches this way.

Gale