When we adopted our chickens from a friend they gave us EVERYTHING they had for the chickens including a metal watering can that should automatically fill. Of course our little turds kick dirt and feed into the "lip" of the waterer and things get clogged up. My question is.... Is it typical for this type of watering system to turn the water black and have an oily film on it after about 2-3 days? Some possible important information to help answer my question - We live in Mesa, Az (hot), our water is pretty hard, watering can is kept in the shade all day and is raised off the ground by pavers. Any helpful information would be greatly appreciated. TIA