We kept our chicks in a seperate (rabbit) cage in one corner of the coop until they were about 6 weeks - when we determined they were outgrowing the small cage. This made it easy to keep them on Starter/Grower food, and the adults on Layer feed. We let them all out into the yard to scratch for bugs and worms and eat grass as well. The starter food has more protein and minerals in it, to encourage healthy bones and muscles; but less calcium than layers require. Now we mix 50% of each kind of food into the feeder, because what was happening was the adults were eating the chick feed and the chicks were eating the adult food. They are all healthy at 12 weeks. We will switch them all to poultry layer at 18 weeks as directed on the label. We also supplement with some crushed up cereal (primarily Strawberry Mini-Wheats and Cheerios) in a small treat bowl, which they look forward to!