You're no doubt familiar with the conventional products filtering tap water. They typically filter calcium from the water and reduce the content of any substances that lend the water an unpleasant odor or taste. But what if you live in an area with very hard water that causes limescale deposits in household appliances, where conventional filter cartridges are inadequate of protecting against limescale deposits? The BWT filter cartridge for Soft Filtered Water EXTRA is used in particular to treat water with a high degree of hardness. This reliable reduction of the water hardness protects household appliances from limescale deposits. This filter was specifically developed to reduce the heavy metals content in water (e.g. lead, copper) as well as substances that lend water an unpleasant odour and/or taste, like chlorine. The result is a transformation of tap water into a premium-​quality taste sensation. For very hard water Less chlorine and fewer heavy metals Extra limescale protection Better limescale protection in very hard water areas No plastic bottles Never have to carry water bottles back from the shop again