Comprehensive supplement for the planted aquarium * Contains a rich assortment of important micro elements, trace elements and other nutrients including calcium, magnesium, and iron * These elements have been shown to be beneficial to aquatic plants * For macro element fertilization (NPK) use Flourish Nitrogen, Flourish Phosphorus, or Flourish Potassium as needed * 250 milliliters treats 100 gallons for 4 to 6 months