Hikari Marine-S is a daily diet for all small marine fishes. Manufactured using essential fatty acids and high-quality proteins, Marine -S helps improve immunity to the disease brought about by stress associated with life in an enclosed marine environment, allowing them to live a longer healthier life. Marine -S becomes sponge-like rapidly yet won't dissolve. It sinks slowly allowing fish at all levels of the aquarium ready access to its nutrition. Will not cloud water.