Thank you for that. Looks like I learned something new today.Nice Incubator!
Yes, they are generally harder to hatch because of the shell and coating. They have moisture issues and often they are so dark that it is hard to see into them.
If shipping stress is added, you can get very low hatch rates from them.
Yes they are very hard to see through. "When in doubt - don't take it out". I candled again on day 18 and got one wrong. There was nothing in it, but I just couldn't see it.
Well sounds like my 50 % rate is quite acceptable