Oh - I also sprayed my eggs down with 3% hydrogen peroxide and let them dry prior to setting them. The eggs arrived very dirty, and I didn't want to wash them off. Three that have been culled had indications of bacteria in them - one that smelled horrid after five days of incubation, and had a large air pocket going in, which I suspect was old to start with. The other two had no odor. One showed no development, and was culled as such, which had a very thick, slimy membrane and a yolk diffused through the albumen when examined. The third started to develop but failed early, and the embryo was brown and slimy. I suspect all three eggs came from the same hen, and that she had an internal infection, since to me it looked like the bacteria were already in the egg. The other six I've culled never developed any veins, and candled clear. Day 10 candling for development is in an hour or so, for best visibility.