I agree with the above posts. I have candled sporadically during the half a dozen hatches I've done, but I'm no expert, so unless I've got a totally clear egg at day 18 when they come out of the turner they all stay through the hatch unless I see reason to take them out otherwise (weeping, smelly, etc). My hatches are getting increasingly better as I learn more and get "better" at the incubation process. I can't control the fertility besides using "good" eggs from "good" stock, so I wait it out and see how things go
