Bottom line first, out of the 20 eggs, none made it to hatch.
3 were well formed and about to hatch; 2 were well on their way. The rest were either just starting to form or were duds from the beginning. I do not think any of them drowned; I think they overheated.
Given the incubator I was using, this is what I have learned:
- Because the thermometer was on the same level as the eggs, the temperature should have been at about 100F, not 101-102. Heat rises.
- I think the 40-45% humidity was OK.
- The big error was blocking the vents, all but one, following the article on dry incubation (unless I completely read it wrong). That raised the temperature to about 103F where the thermometer was. Therefore, the temperature above the eggs was hotter.
- Had I left all the vents open, I think I could have had the 3 chicks I was expecting.
And/or borrow a different incubator from a trusted friend who has found that using totally dry incubation in his forced air incubator is working best.