Ok so I'm seeing all of you people with really big dogs purchasing the natural and holistic "healthier" dog foods that I don't necessarily believe in. Personally I feed my dogs a combination of purina and home added ingredients they may need for a while to target specific problems such as shedding. Anyway, I know that you are not supposed to purchase large bags of dog food unless you store them correctly so they don't go bad. We buy 40 pound bags, one for each dog as Pepper get senior food and Autumn gets weight loss, and they last maybe a month and a half each. We store them in our pantry which is cool and very dry and the bags are kept air tight. So my question, as I've only seen up to 10 pound bags of some of the foods you guys mention, is how often do you purchase dog food and what size bags do you get?