hello i have layers that are nearly there and i have two that need to start again!!! ( they had chicks and no eggs for me in 15 weeks+) i want to swap them back to the layers BUT i have one chick and i think "he" is about 12 weeks this saturday , i have been told that young chicks cannot deal with the high calcium is 12 weeks still too young or can he deal with it now? they do have oyster shell and grit ect on hand already but they dont seem to touch it at all any advice will be great i want eggs again !!!