I recently have started maintaining a bird bath in the?backyard that's attracting a lot of juncos, a few pine siskins, and rarely a black squirrel or chickadee. The juncos love to bathe especially on sunny afternoons and I even suspect one or two birds are dominating over others in having access to the bath. The juncos almost form a waiting line on the nearby hedge because as soon as one is done, the next one will pop in from the hedge. The bird bath is made of stone, and is shallow (less than an inch of water) and wide (less than 2 feet in diameter). While I change the water daily in the morning, I often discover bird droppings either in the bath or on the edge when I do this. For now I just rinse it out with a coarse brush and plain water, but I'm wondering if it needs more aggressive cleanings with either soap, vinegar, etc. At some point in the future I'd like to install a small water fountain (one used in an aquarium) that can throw water up about 3 inches. What is the general advice for maintenance of a healthy bird bath?