I give my two girls a standard layer crumble, plus they have ground to scratch. Occasionally they get a tomato or some bread, but other than that I don't do calcium or minerals or anything else. Is that enough? The eggs are delicious and have a good shell, and the girls seem happy and peaceful. Am I missing something? Also, if I get more layers of about the same age, how long do I need to keep them separated before they can all hang together? TIA!