Features: 1.[Good Nanotechnology] Aquarium filter ball is actually sintered at high temperature using nanotechnology, and it is full of tiny pores, corrosion resistance, high temperature resistance, and not easy to pulverize. 2.[Purify Water] Aquarium filter media provides a breeding ground for nitrifying bacteria to multiply and survive, so that nitrifying bacteria can survive in large numbers, promote water quality decomposition. 3.[Irregular Circular Design and Pore ??Structure] Aquarium bio balls have an innovative irregular circular design with a pore structure that facilitates the attachment and growth of nitrifying bacteria. 4.[High Efficiency] Fish tank bio ball has super adsorption power and can efficiently absorb peculiar smell in the fish tank, greatly improve the effect of the filter system. 5.[Bacteria Culturing] After using aquariums bio filtration media, the water is clear and odourless rapid culture of bacteria to stabilize pH. It helps to improve your fish tank that is cloudy, green and yellow. Specification: Item Type: Aquarium Bio Balls_x000D_ Material: Bacteria Balls_x000D_ Use: Aquarium, Fish Tank Filtration_x000D_ Net Weight: Approx. 500g_x000D_ There is 0-5g error. PackageList: 1 Bag x AquariumBioBalls Note There is 0?5g error.