Fast-acting API POND ALGAEFIX Algae Control works to control algae growth in ponds, water gardens, and fountains, keeping water clean and clear. API POND ALGAEFIX Algae Control works to control Green or Green water algae, String or Hair algae and Blanketweed. Will not harm fish and plants when used as directed. API POND ALGAEFIX Algae Control is for pond and fountain use only, where water is contained without any outflow. Ponds must have adequate aeration to maintain sufficient oxygen levels for fish, especially in warmer weather. To determine accurate dosing for your pond size, measure the pond volume before use. Do not use with freshwater crustaceans, including shrimp, crabs, and lobsters. With API POND products, it?s easy to keep a beautiful pond. For over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your pond. API POND Pond Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as koi, catfish, perch, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your pond. Make sure to use all products as directed in order to ensure the best results.