After reading thru some posts I missed, thought id ask y'all (sorry originally from the South). I read somewhere that when you have dark eggs, like marans, sand some color off in lines around the eggs presumably for candling. Of course then I read do not wash off the bloom everywhere else. What is your experience? I could try half and half I suppose.
I wouldn't intentionally remove the bloom. I wait to candle Marans and Welsummers until they are about 2 weeks old, then it's easy to see the contrast between the air cell and the chick's body. Any that don't have that sharp distinction are not fertile and get tossed.