Hikari Tropical Algae Wafers are scientifically developed sinking discs designed especially for plecostomus and other algae-eating fish, including marine herbivores. These wafers contain a higher level of vegetable matter and multiple algae types that algae eaters instinctively prefer. It delivers essential nutrients to help support proper growth and a healthy body form in most herbivore species. The unique, rapid-sinking shape stays intact longer in water, giving even less aggressive eaters plenty of time to access their food. With pure-cultured spirulina and chlorella algae included, these algae wafers help your aquatic pets look their best, always.