GreenClean GRANULAR ALGAECIDE GreenClean is a granular algaecide that is safe for use in all water features such as water gardens, ornamental waterfalls, fountains, bird baths and ponds. It is effective on all types of algae and when diluted in water, is completely safe to use around ornamental plants and all fish and wildlife. It works by creating a powerful oxidation reaction which breaks down algae cells on contact. It begins working within 60 seconds of application and results can be seen in as little as 24 hours. GreenClean is EPA registered. A 2 lb. container will curatively treat a 1000 gallon pond for an entire season and an 8 lb. container will curatively treat a 4000 gallon pond for an entire season. With heavy growth of algae, recommended dosage is up to 1/2 lb. per 1000 gallons or 1 lb. per 2000 gallons.