I have the chance to buy this feeder, http://webstore.stockdales.com/Main/Item.aspx?fl=-2147483123&m=-2147482030&ii=21300, the couple that are selling them have 3, i'm getting a great price, i hope to have 25 chickens by spring. want the larger breeds Black australopes, ect. So the question is, do I need 2 or 3 of the 5 gallon? I'm not wanting to fill and not fill up for a week, i'm wanting to make sure everyone gets a chance at the table. suggestions? I pick up tommorrow at 3:00.