getting calcium to layers when mixed in with chicks?

[hennyjenn]

I'm looking for a handy way to offer my laying hens extra calcium without the 7 week old chicks getting it. They have been sharing a coop for about 5 days and all is going well. Everyone is eating flock raiser, as we also have a few ducks. How do you offer your older chickens calcium?

 

[A.T. Hagan]

Hang a hopper of ground oyster shell where the layers can get at it. No one else will bother with it.

 

[abelseville]

So if chickens don't need extra calcium they instinctively know not to eat the oyster shell?

How much calcium does this flock raiser have in it? How is it different from starter ration?