Just discovered this the other day. My husband bought the chicks food when they were about 2 weeks old (we'd been given enough to get them through that time) He bought grower finisher and not starter grower They seem to be doing ok, but now I'm worried about their development. They are 7 weeks now and growing like weeds. Should I change them back over to the starter food? Or are they old enough to be on the grower now? Thanks.