1.The fish tank filter provides effective filtration and increases the oxygen level to ensure a clean tank environment. It features fine cleaning effect, quietness and easy maintenance. Fit for shrimp, fry and various ornamental fish like betta, discus, guppy, and goldfish. 2.Fish tank filter provides both mechanical and biological filtration for your tank. The air infusion chamber produces numerous minute bubbles which promotes gas exchange process and increases dissolved oxygen level in water. Good to use in both fresh and saltwater tanks. 3.The sponge traps waste particles mechanically and cleans the water without trapping baby fish. It keeps water clean and clear.