Zoo Med's new Spirulina 20 fish food sinking sticks are made from a blue-green plant plankton rich in raw protein and seven major vitamins: A₁, B₁, B₂, B₆, B₁₂, C and E. It naturally contains beta carotene, color-enhancing pigments, and a whole range of minerals. In addition, it contains all essential fatty acids and the eight amino acids required for complete nutrition.