i have 17 chicks in all. i still have a 100 watt light on them 24/7 in the coop. there mostly feathersed all but a couple smaller chicks. i built a 12ft long by 6ft wide by 4 ft high run for them . so they can go out side during the day. made from a 50ft roll of 1inch mesh poultry netting and i covered the top of the run with the wire also to keep out chicken hawks. just in case. they have never bothered the bigger flock. but u never know with the litle ones. so when should i start letting them out in the run.