Jcatblum, are you finding the shells on these eggs paper thin? I would think a big egg house like that would supply their birds plenty of calcium. Also, Ronnie and I have found a bunch of soft shelled eggs. Wonder if that is stress related from their move from the world they have known their whole lives to this alien planet called Earth. They should be getting plenty of calcium now, though. We include %5 oyster shell in our Carnegie feed mix and now have a couple of bowls of it around for them to eat free choice.
Lack of sunlight will also make the shells thin. You might put some vitamins in their water for a time until their bodies catch up with the change.
Since they are getting a good balanced diet now I would mix it at 1/2 of what the packet says.