Reef Phytoplankton is a concentrated blend of green and brown marine phytoplankton designed to provide the essential fatty acids, proteins, vitamins, amino acids, with biological carotenoids for invertebrate diet. Reef Phytoplankton contains a natural source of carotenoids which provides essential proteins as well as a more bioavailable source of pigmentation when compared to other natural sources and synthetic pigments. Carotenoids provide the extra benefit of antioxidant activity.