The Oscar Enterprises Surface Skimmer removes the unsightly and problematic organic film from the surface of your home aquarium’s water. The surface skimmer is excellent for heavily planted tanks where a lack of surface agitation often results in an organic “oil slick". Includes suction cup to firmly secure the unit to inside of any aquarium and attaches to most common canister and hang-on power filters. The surface inlet is designed to float on the water surface can be adjusted to sit 2-4 mm below water surface to "skim" the top few millimeters of the water surface.