This is my first winter with ducks. I heard that they can do fine without a swimming pool as long as they have a bucket of water deep enough to wash out their eyes and nostrils. I assume that water needs to be CLEAN. However, ducks backwash their food and mud into the water. How do you have water dedicated to head washing without their spoiling the water? Of course, you would change out the water every day, but is that really good enough?