Easy-to-use biological filter for tropical aquarium fish Aquarium filter sponge for efficient biological filtration Great biological filter for breeding or spawning aquariums Produced from high-quality hydrophilic filter material. Multi-strata design provides a large surface area for optimum filtration. Provides the ideal location for bacterial colonization. Operated by an air pump to create numerous minute bubbles to increase dissolved oxygen content. A replaceable filter sponge allows long-lasting use. Do not trap fish fry. Suitable filter when breeding and spawning Discus, Dwarf cichlids, guppies, and killifish. These filters allow you to cultivate nitrifying bacteria for superb biological filtration. Great for fry aquariums and brine shrimp hatcheries because they prevent young fry from being trapped in the filter media. Operates silently, creating numerous minute bubbles for increased oxygen flow. Each requires an air pump and airline tubing, sold separately. Maintenance Rinse the sponge with cool or warm running water weekly. Do NOT use hot or very cold water as this will destroy the bacteria which colonize the sponge. Do not use soap or detergent when rinsing the sponge. Model: XY-2831 Dimension: 5"L x 1.8"W x 5.5" H Max Tank Size: 10 Gallon