Vitamin and amino acid supplement. Iodide supplement for freshwater fish. Helps prevent diseases developed from thyroid deficiencies. Nourish is a complete vitamin, amino acid and trace element supplement developed to meet the nutritional needs commonly found in freshwater aquarium ornamental fish. Nourish contains potassium iodide through spirulina and chlorella. Spirulina and chlorella contain a rich assortment of amino acids and vitamins. Nourish can be used on marine ornamental fish, however, it is specially designed for freshwater fish. 250 ml treats 250 l.