MULTIFUNCTIONAL AQUARIUM FILTER: BYKAELER multifunctional aquarium filter has the function of filtration, aeration and surface skimming oil, purifying the water quality of fish tank, with its own micro-oxygenation function, adjusting the flow of water and oxygen through the flow control knob. Meet the needs of all types of fish tanks.AQUARIUM HANG ON FILTER:The small external aquarium filter runs at 85GPH (400L/H) . Support low water level operation, recommended for 20-30 gallon freshwater fish tank, turtle tank and aquarium..SUPER FILTRATION: the small fish tank filter has 5 layers of filtration, the fish filter with filter sponge helps filter dirt and debris to help keep the tank clean and healthy, you can freely place different filter materials according to your needs..ULTRA-QUIET OPERATION: 360° fully sealed filter to avoid noise from air seeping into it. It adopts a copper brushless motor for ultra-quiet operation, while reducing energy consumption and saving power and energy. The bottom of the filter is equipped with a vibration-absorbing pad, which can effectively reduce vibration..INSTRUCTIONS FOR USE: The aquarium canister filter must be filled with water before it is plugged in for the first time. If there is noise during use, it may be that the air is not discharged cleanly, and the air can be discharged quickly by adjusting the water flow control knob.