So, a friend of mine wants fertilized ducks eggs, and I volunteered as we have a male and female. So, what's the best way to candle the eggs? I mean, I can set out a few eggs or so in a bowl on the counter (dated, of course) and candle them in about a week, right? She has an incubator, but I don't have one yet. When is the best time to candle...time frame, that is? Thanks!