Hello, I am incubating 4 duck eggs at the moment and it is day 6 I think, 3 are developing nicely. I noticed after candling last night, one has a crack in it. It is a nice size crack. Its not oozing and the veining is beautiful. Will it prematurely crack open when the duck increases in size? Is there a way to keep the crack closed? ( It was worth a try to ask ) Thanks..