When purchasing water purification equipment in the northern region, the softened water quality is emphasized. It is recommended to select the combination of central softener and terminal water purifier. Among them, the central water softener softens the water quality through the resin exchange principle, and the end water purifier makes the water quality reach the direct drinking level through the filtration of high-precision RO reverse osmosis filter element. Nobana central softener can remove more than 90% of the hardness. It can soften all the water used by the whole family, and make the family more comfortable and secure no matter whether it is bathing or cleaning.