Function: The Air Driven Bio Filter Sponge Filter is perfect for aquarium, providing both mechanical and biological filtration, which can remove waste and maintain clean water for your fish efficiently. The Bio Sponge Filter can produce masses of airbubbles, which will help to promote gas exchange and increase dissolved oxygen level in the tank water. Easy to Install or Clean: For installation - Just connect the Bio Sponge Filter to the air pump by airline tubing. For Cleaning - If the sponge becomes dirty, you can take it out and squeeze it by using the water for fish; Remember to clean the crackedstones regularly. For the Media - You can add biological media like biohome gravel, or change it to your preferred media and some poly floss. Unique Design: The are designed with soft sponge material, traps floating debris, and the multi-layer shape increases the surface area to get a better water and oxygen exchange rate, will be safe for small size fish like betta, dwarf cichlid, guppy, killifishetc. Fitted Fish Tank Size: Recommended 1 to 5 Gallons, you can place it in the aquarium corner or hide it behind plants, suitable for small tanks or small fry containers, such as shrimp tank, betta tank, breeder tank, goldfish, snails, discus, guppies, fry,baby fish etc.