Cow dung is usually added to a fish pond in order to encourage the growth of

Cow dung is usually added to a fish pond in order to encourage the growth of phytoplankton and zooplankton. Cow dung contains nutrients such as nitrogen, phosphorus, and potassium, which are essential for the growth of algae and other aquatic plants. These aquatic plants form the base of the food chain in a fish pond by providing a source of food for zooplankton, which in turn are eaten by small fish, and so on up the food chain. Therefore, adding cow dung to a fish pond can help increase the amount of phytoplankton and zooplankton in the water, ultimately leading to a healthier and more productive fish population.