I feed layer crumble and spinkle in some oyster shell, they get scratch grains corn, and i give veggies , kale , lettuce, and melons berries etc. And they free range all day , so they actually dont eat a whole lot of the layer feed and oyster shell. The egg shells are very hard compared to grocery store eggs which I know is normal as these are healthier chickens but a couple eggs every day have some little extra bumps on them, ( looks like would be painful to lay them ) and I am wondering if they are Over supplemented on calcium and should I stop adding any oyster shell.??? They only started laying a couple months ago, I have 17 hens and 2 roosters. They were born in June.