CrystalClear PondShock is a great alternative to chemicals to clear your pond water fast. The organic ball contains billions of all natural, live bacteria and enzymes that are designed to rapidly break down ammonia, nitrites and organic waste. Can be used in the spring to jump-start biological filters, when water quality issues escalate or before new fish are introduced to the pond. Use once a month or as needed when water temperatures are above 50 degrees Farenheit. Safe for all aquatic life.