Seachem Flourish Fertilizer Tabs are tablets that stimulate the root structure of aquatic plants. It contains essential trace minerals, which are needed to ensure each plant is healthy. These tablets are rich in iron, manganese, magnesium, calcium, potassium, inositol, choline B12, and biotin; all of which are essential for the prosperous growth of aquatic plants. These fertilizers are available only in tablet form and easily dissolve directly in the tank. A ten gallon tank requires the use of six tablets, once every three months.