Fluval U3 Underwater Filter is ideal for use in all aquarium or reptile environments. Use the underwater filter as a primary filter in smaller aquariums or as a supplementary filter for larger aquariums. Fluval Underwater Filters with three-stage filtration are ideal for use in fresh, marine or reptile environments, and are also great for tanks with low water levels. Three-stage filtration with BioMax for superior aquarium water quality, flip-top access for quick and easy cartridge replacement, and three-way flow control make the new Fluval U Series the benchmark in underwater filtration. Stage 1 foam removes large particles. In stage 2, the poly/carbon cartridge traps fine debris, improves water clarity and removes impurities. In stage 3, BioMax provides optimal biological filtration efficiency. For more fish tank accessories, check out other Fluval products including aquarium filters, aquarium heaters, aquarium air pumps, aquarium lights, aquarium rocks, aquarium thermometers, and aquarium stands. Fluval has a wide variety of products that are perfect for your pet fish to enjoy in any large fish tank, small fish tank, saltwater tank or freshwater tank. Fluval broke onto the aquatic scene in 1975 by introducing the world?s first 3-stage filter with synchronous motor technology - a breakthrough that is still applied in the industry today. Since then, Fluval has built a legacy around this pioneering spirit, relentlessly adapting in a changing world to launch innovative aquarium products that remain at the forefront of technology, and which set the bar in quality, style and functionality. Fluval?s mission is not just about building products that mimic the natural world, but inspiring aquarists of all skill levels to enjoy and respect the hobby for generations to come.