Humanized cover design, prevent from leakage meanwhile absorb the dirty objects. - Built in replaceable filter tank and special strong bioactive beads, It can achieve better the physical filtration effect and provide space for the nitrifying bacteria to attach. - Multi-functional: Oxygen aeration, enhanced the filtering effect of organism and improve the stability of water quality of aquarium. - Easy to use: You just need to connect to the discharging air pipe, put in water and open the air pump to clean the fish tank dirt.