I am new to the chicken world and my 9 Plymouth Rock females are 3 weeks old and growing fast. They are currently in a 75 gal Rubbermaid stock tank. My two questions are this. I know I am supposed to keep them in the brooder for 6-8 weeks, but since they are getting really rambunctious in the stock tank, what are the possible negatives to giving them the run of the chicken coop earlier than the 6-8 week recommendation?. The coop is very secure, weather tight and insulated. I would still hang the heat lamp so they could be under it if needed, and the feed and water would also be available. How does one determine how high to initially position the roost? I am going to have one long pole (10 feet) for them to roost on. Do I start at one foot and keep raising it? What is the optimum final height?