Same as FortCluck. Mine have access to a 5 gallon bucket they eat from as they want. The bucket is in the coop year long, the chickens don't free range in my area because predators are abundant, but the rare times I've sprayed feed in the run for them to scratch at last year, any squirrel found nibbling on it was chased out by my ladies. So rodent-wise, I've got no problem for the chicken feed x3
I've got 7 hens plus 1 rooster right now, and together they go through a 25kg feed sac in 3-6-ish weeks, I've never kept a real count on how much feed they ate, but I know I can last a while with a single sac here. The tube feeder is excellent to ensure no feed is wasted, even the crumbles who end up ground into fine powder by the weight of the feed get eaten just fine. Other types of feeders might not 'help' chickens gulp down this fine powder though, and if they can see their food, they will definitely spill all the powdery feed to get at the bigger grains.