Bio Balls Filters solve the problem of more impurities in the and makes the fish live healthier.Bio Balls Filter Media reduces the growth and of harmful substances by algae. The sufficient amount of them can be used for an enough time. The design of hollow sphere made of plastic material,which has a large surface area and then can attach a large amount of nitrifying , Aquarium Filter Media Bio Balls can help clean your naturally. Features -Color:Black -Material:PVC -Size:2.60X2.60X2.60cm/1.02X1.02X1.02in -Forming a rapid filtration rate, and a large amount of interception of dirty materials. -Lightweight, and high strength, the Bio Balls are stable and have chemical properties, which are durable. -With the flow of , the filling gaps become larger and less likely to be blocked. -Large specific surface area, strong activity, good effect. Being reusable saves money and effort. -Fine workmanship and creative appearance popularity and practicality. Package list: Aquatic Bio Balls