GreenClean pH UP slowly raises the pH of pond water, making it more alkaline. Keeping pH levels in a neutral range is essential for the health of aquatic life, plants and the pond ecosystem. An unbalanced pH level suppresses the proper amount of nutrients aquatic plants need to thrive and is a major cause of fish stress and disease. When pH levels are too low (acidic) your water is out of balance and the environment promotes algae growth and unpleasant odor. By maintaining a neutral pH range, 6.8–7.8, water features are clean and healthy. This easy-to-use product will not promote algae growth and is safe for fish and delicate aquatic plants.