It can be difficult to candle quail eggs due to the shell colour. The coturnix are hard to see into and the button eggs are darn near impossible. I use a super bright led flashlight on the fat end of the egg. I candle when I set them to look for cracks in the shell, and then I candle again around day 10. By then it should have developed enough that the egg should appear dark inside except for the air cell. Look closely at the line between the air cell and the rest of the egg. It should be a clear, well defined line. If the line is murky, the egg has usually quit.
The other thing you can do, is take the spots off the eggs. They will actually rub off with a nice warm damp cloth. Some people will jump up and down about disturbing the flora on the egg shell but that's more of a concern with natural incubation under a broody hen.
The other thing you can do, is take the spots off the eggs. They will actually rub off with a nice warm damp cloth. Some people will jump up and down about disturbing the flora on the egg shell but that's more of a concern with natural incubation under a broody hen.
