I want to start fermenting my chicken's food, and I need to know what kind of bowl/feeding trough I can use that the chickens won't knock over. I bought one of those rubber feed bowls at the farm store and the smell is terrible: I don't want to use it for my girls because the smell gives me a headache and I know that birds have sensitive respiratory systems. What kind of heavy, non-breakable dish can I use in the run?