Thought I had three unfertile eggs and all were developing at day ten in my incubator. I also broke two of which one was fertile. I candled and those three were all fertile. My eggs vary in size and color. I have four browns, two Rhode Island(yearling's) and various aged rescued hens with three Rhode Island Reds roosters and an aged disabled rescued rooster so egg colors vary and are difficult to candle. I get pretty upset when I destroy a viable embryo. (birds are my weakness and I can tame and pet pretty much anything) I've heard if you leave an undeveloped egg in the bator and it explodes it will destroy the entire batch. Any advice on candling and sorting developing incubator eggs would be GREATLY appreciated!