Flourish is a comprehensive plant supplement for the natural freshwater aquarium. It contains a rich assortment of important micro elements; trace elements and other nutrients. Flourish is rich in gluconate iron; manganese; calcium; magnesium; potassium; inositol; choline B12; biotin; and other factors that have been determined to be beneficial to aquatic plants. For macro element (NPK) fertilization; use Flourish Nitrogen; Flourish Phosphorus or Flourish Potassium as needed. 67.6 oz. bottle treats 800 gallons for 4-6 months.