At what age can I switch from starter to flock raiser? The ages in my flock are all over the place from my 4 5-6 week olds in the brooder on medicated starter but getting close enough I think to move outside, 4 who are about 10 weeks, 12 who are about 16weeks, and a huge girl who is about 24 weeks. No body is laying but 2 are getting close I hope. They have a dish of oyster shell incase someone wants it, free range 99% of their awake hours, and have chewed through 1 3/4 flock blocks now. I would just prefer them on pellets and cant find it in starter.