WHOLE HOUSE WATER FILTER SYSTEM: Catalytic Carbon 10″x54″ TANK Filtration System. Catalytic Carbon In/Out Filter System are highly popular because they correct a wide range of water quality problems, by reducing chloramines, hydrogen sulfide, and tastes, odors, chlorine & sediment. 12 x 40 mesh catalytic carbon. Great tasting water from every tap in your house. No bad tastes or foul odors. Crystal clear water for drinking, bathing, and cooking. User friendly equipment. Low maintenance. This system uses 12×40 mesh catalytic, high activity granular activated carbon manufactured by steam activation of select coconut shell charcoal. The catalytic activity of this activated carbon makes it highly effective for the reduction of chloramines and hydrogen sulfide from potable water. Its large micropore volume makes it particularly well suited for the reduction of low molecular weight organic compounds and their chlorinated by-products such as chloroform and other trihalomethanes, THM’s.