Healthy Ponds 52200 All Purpose Water Cleaner 10 - Preloaded Dispenser 2 Pack; Each Dispenser Treats up to 10 Gallons for 15 Days Keeps bird baths, fish bowls and water features up to 10 gallons clean, clear and free of green organic growth Unique patented time-release system delivers a proprietary blend of naturally occurring bacteria and enzymes into the water for 15 days Veterinarian approved and safe for fish, plants, birds, animals and humans Results may vary; over time bacteria and enzymes will work to reduce organic debris, improving water quality and clarity while eliminating odor Includes 2 preloaded dispensers; each dispenser treats up to 10 gallons for 15 days