Seachem Nourish 500ml Vitamin and amino acid supplement Enhanced with iodide for freshwater fish Helps prevent diseases developed from deficiency-thyroid ailments Nourish is a comprehensive vitamin, amino acid, and trace element supplement developed to address nutritional requirements commonly associated with long term closed system housing of freshwater ornamental fish. Nourish contains potassium iodide in a heavy base of spirulina and chlorella. The nutrient iodine is essential for the biosynthesis of the thyroid hormones thyroxine and triiodothyronine. * Both spirulina and chlorella contain a rich assortment of amino acids and vitamins. Nourish can be used on marine ornamental fish; however, it is specifically designed for freshwater fish. Directions Shake well before using. For best results, soak fish food, such as Seachem's NutriDiet Flakes, in one capful of Nourish daily.