If I am only buying 5 chicks (probably red sex-link) what size bag of feed should I purchase? I've read through this forum, the reviews, and the learning center, but I've yet to find how much I can expect a chick to consume. If I buy a 50# bag, and they don't use it all before they start laying, can I continue to mix the starter in with the layer until it is used up? How long will a bag of food last if it is kept well? If I'm using 50# over 18-22 weeks will it start to spoil/mold/sprout? Thanks for helping this newby out!