1pcs NanoBiochemical Ball House Filter Media Nitrifying Bacteria House Aquarium Filter Accessories For Fish Tank Water Cleaning Features: 1, Sintered at a high temperature of 1800 degrees, it has a significant effect on inducing the color of fish 2, Full of rich variety of natural elements and essential minerals and trace elements. 3, Stable PH valve. Great help to restore the natural water quality, and provide the most suitable living environment for your fishes. 4, suitalbe for fresh water and sea water tank. 5,The fine micropores are conducive to the reproduction of nitrifying bacteria and adsorbs more harmful substances 6,Add far-infrared element, promote fish metabolism and excrete harmful substances in the body, remove heavy metal elements in water. Attention: 1, After transportation, the bio balls may have ceramic dust on surface. Thanks for understanding. 2, The new bio balls should be washed with fresh water before usage and then you had better put them in boiling water for 20 minutes. 3, After using the balls in fish tank , if the balls need to be washed , wash it with aquarium water , do not use tap or boiled water. Speicificaitons: Model:Nano Bio House Filter Media Color: Yellow/Grey Size: 9cmx2.5cm, 15.5cmx3.5cm Package include: 1pcs Aquarium Filter Media/2pcs Aquarium Filter Media