Well, in about 16 days, I have 2 sets of Silkie eggs hatching. They hatch on the same day. One batch is from my silkies around 5 eggs, and One batch is from another breeder (around 8 eggs, need to check fertility). I want to have the chicks hatch seperate so that I can mark them from which breeder they came from. I was thinking of taking a strip of cardboard maybe, 4" tall and running it down the middle of the incubator. It is a Hovabator 1602N. Would that work? I would put my eggs on one side, and the other breeders eggs on the other side?I cant let them hatch in my Brinsea because I have other eggs that will be on around day 18, and I dont want to risk that hatch. Or would it be fine to have one batch of eggs on day day 21 and day 18 in the same incubator to hatch. (I would put the other day 21 eggs in the hovabator) I would have to open up the incubator quick, after the eggs are done hatching. Would that effect the day 18 eggs negatively?