Hi All! I have 17 chicks that are 10 weeks old now. They've been in the coop for 4 weeks now with heat lamps round the clock . It is low 30's -20's here at night. Is it time to turn the lights off and let them get used to the weather? If it's super cold we've turned them on in the past with a prior group...but have never started with fall chicks before. Any advice would be appreciated. Thanks!!!