I have one hen who has of late been laying soft shelled eggs. I have recently raised 8 pullets and a Cockrell and added them to my flock. A couple weeks ago I integrated my flock and at that time changed my feed to an "all flock". I supply oyster shell and once or twice a week crush their shells and add it to a yummy mash that I make for them. Since then my black sex link has been mostly laying soft shelled eggs. The rest of the hens seem to be fine with the feed change and eggs look fine. What can I do to help this one hen without giving the pullets to much calcium? Today I added ACV to the water in case it's an absorption problem...anything else I can do?