Aqueon QuietFlow Internal Power Filters are ideal for aquarium or terrarium use. They are fully submersible in a vertical or horizontal position. The filters offer water flow return controllability in a variety of ways: adjustable flow rates, adjustable flow direction and adjustable flow height. Three stage filtration: dense foam for particles and debris, activated carbon for toxins, odors and discoloration and patented BioGrid for ammonia and nitrates.