Herbivores are grazers and need a constant supply of plant foods. In addition to feeding the Herbivore Blend, you should be providing greens for all-day grazing. Seaweed Blend provides three types of dry seaweed in one package: (1) high-quality green sheets, (2) certified raw (nutrient-rich) red sheets, and (3) a raw, leafy, purple seaweed. These make it possible to offer a variety of greens. Your tangs will love it.