100% Natural. Eliminates Green Water. Reduces ammonia and nitrogen levels by dissolving organic waste. Reduces buildup of bird droppings, fish feed, and dead leaves. Breaks down dead algae. Improves dissolved oxygen levels thereby creating a health environment for your pond and promoting faster fish growth. Gallon size great for medium and large ponds. Gallon treats 501-1000 gallon pond. 1st application: 12 oz. Next 4 weeks once per week: 4 oz. Maintence once per month: 4 oz. 1001 - 5000 gallon pond. 1st application: 16 oz. Next 4 weeks once per week: 6 oz. Maintence once per month: 6 oz.