3 days of high humidity for the lock-down is best, but like I said, I have had keets hatch early in the turner, with only 45-50% humidity (determined lil buggers). Had I not raised the humidity for the others right then, I doubt they all would have hatched successfully tho. IMO, locking down a day early is safer/less harmful than locking down a day late... at least with my hatches. The keets need the extra moisture so they can spin around in the shell zipping the top off, and stay moist enough to get out of the shell.
Candling really is a learning experience, looking at pics (most;y of chicken egg candling) definitely helped me, but candling my eggs in the incubator and then comparing them to what I saw when I candled a non incubated egg also helped me see the early development, each time I candled. Towards the end of incubation, once the keets has fully formed enough to fill the egg you don't see much other than a dark mass filled egg and an air cell...and then the air cell changes shape and starts getting bigger, with the size increasing at a slant, not just up at the top of the egg when it's getting close to hatching. I've tried and tried and TRIED to take some decent candling pics, with no luck. My crappy cameras just can't handle it.
Candling really is a learning experience, looking at pics (most;y of chicken egg candling) definitely helped me, but candling my eggs in the incubator and then comparing them to what I saw when I candled a non incubated egg also helped me see the early development, each time I candled. Towards the end of incubation, once the keets has fully formed enough to fill the egg you don't see much other than a dark mass filled egg and an air cell...and then the air cell changes shape and starts getting bigger, with the size increasing at a slant, not just up at the top of the egg when it's getting close to hatching. I've tried and tried and TRIED to take some decent candling pics, with no luck. My crappy cameras just can't handle it.