The guy at the feed store told me to start using Layena crumble. Our girls are 6 weeks for four of them and 7 weeks for the other. I asked him about using the 'red' bag of start and grow, but he said the only difference between that bag was the it was medicated. Should I stay with chick mash? or use the Layena? This is our first batch, even though only 5, just don't want to have a problem. They get out of their coop/run and help with the weeds and bugs for an hour or so daily and get some extra greens a few days a week.