Well, I bought a new strong flashlight today and candled all my eggs.
I found that out of about 48 I only have 18 that have chicks. I did purchase mostly inexpensive eggs because I didn't want to try with expensive eggs again, but I would have thought that more would have been fertile.
My bantam favorolles were all infertile except for one. What a disappointement because they were the only expensive ones I bought.
My brahmas were about 1/2 fertile, my silver wyandottes were about 1/2 too.
The cheapo barnyard cross eggs were mostly duds except for a few bantams.
Oh well, at least I have 18. I did see chicks moving in the light colored eggs. The dark eggs I really couldn't see anything. They looked almost black.
I can say, that if the eggs is mostly clear with a roundish dark area in the middle, and there are no dark "spots" then the egg isn't fertile.
Also if the contents sloshes around in there (moves around) it probably isn't fertile either. There is a difference between the whole thing moving and the black spots moving.
Hope this helps.
Gina