Muscovy duck eggs

[pinknose]

I got some muscovy eggs but I don't know if they are fertile. I put them under my broody hen. My question is what is the shortest time that I can candle them?

 

[Griffin Nest]

I candle mine with a REALLY bright light and can see development on day 3

 

[Rare Feathers Farm]

Muscovies take 35-37 days to hatch. I usually don't candle mine until day 9. I haven't had any luck with a hen hatching them out, either. Usually, they will leave the nest after 25-30 days and the Muscovies still need a week or two to go....