The Fluval Moss Ball helps create ideal aquarium conditions for small fish and shrimp by adsorbing and trapping phosphate and nitrite. Use this ball to create an optimal living space for your pet fish. Features: Helps reduce aquarium maintenance by deterring the growth of many of the compounds that cause the unsightly buildup of organic matter Serves as an attractive decorative addition to aquariums Includes: 1 Moss Ball Intended For: Fish & Shrimp Material(s): Plastic Color: Green Instructions: Included Caution: See Instructions Fluval Artificial Aquarium Tank Moss Ball | PetSmart