Im sure this has been asked a million times so one more.. I have 2 18week RIRs and 3 9week old BOs living in harmony. I have about 2 weeks of Start & Grow left I really cant separate them and not sure how I could separate the food so my question is can I add oyster shell and grit to the diet and would the be ok if the reds are ready to start laying. I want some eggs. Once the BOs reach 17 or 18 weeks I would like to start Layena. Any input is appreciated, thanks.