Are duck droppings harmfull to koi?

Yes, duck droppings can be harmful to koi. They can introduce excess nutrients into the water, leading to harmful algae blooms that deplete oxygen levels, which can stress or harm koi. Additionally, duck feces may carry diseases or parasites that can affect the health of the fish. It's important to manage and minimize contamination from wild waterfowl to maintain a healthy pond environment for koi.