They are Barred Rock eggs, brown, but not dark. I am using just a regular LED flashlight to candle, nothing fancy. I just put them in the incubator, but was just wondering when I would be able to tell if they are developing. The eggs were shipped and I am not too optimistic about a good hatch.
You can possibly see veins on day 2 but even with light bantam eggs and a good light source I haven't seen any until day 4. On really dark brown eggs you may never get to see veins. I have no idea what's alive and what's not in my incubator right now except for those that have pipped. I tried everything the past 2 weeks and could not candle those dark brown eggs.
The average time to candle is day 7-10. That's when most can trust what they see. Usually I'll candle day 7, mark the potentially bad ones, check those again day 10-12 and if they don't look like they are growing anything toss them. Then I candle again day 18 when I go to raise the humidity for hatching. Occasionally I'll candle in between those times especially if I still had questionable eggs or eggs I really want to hatch.
I'm doing my first incubation this week and I'm on day 8 i candled yesturday and i'm working with really dark eggs I could see a air sac and a dark area on day 7 so I have been told that means i have growth there was one i'm not sure about that I will check again at day 14 to know for sure if anything is growing.