Premium, research-grade, low-ash Fluval Carbon is highly porous, providing large amounts of surface area for absorption of impurities present in aquarium water. The inner matrix structure provides a large porous area that permanently traps organic waste while removing liquid wastes such as urine, dyes or many other impurities from the water. The activated carbon effectively removes heavy metals, odors, discolorations, organic contaminants and pollutants to leave your aquarium water crystal clear and sparkling. It does not contain phosphates and will not change the pH of the aquarium water. Fluval Carbon is pure activated carbon that is ideal in both fresh and salt water. Fluval first broke onto the aquatic scene in 1975 by introducing the worlds first 3-stage filter with synchronous motor technology a landmark 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. Above and beyond its manufacturing role, Fluval prides itself on its charitable and educational efforts that give back to the fishkeeping community, whether it means helping to fund the protection of wild coral reefs or jumping on a plane to document endangered fish species halfway around the world. Fluvals 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.