Aquarium Air Pumps Battery Syphon Auto Fish Tank Vacuum Gravel Filter Water Change Clean your gravel, siphon the dirt out without requiring a water change  Easy-to-use water change  Adjustable height by two interchangeable pipes of different length, suitable for both shallow and deep aquarium  The new design make it could be used for water level as low as 8 inches.  Battery powered  safe for you and your fish