Water treatment systems are customized and manufactured according to the local water conditions and flow rate requirements. The systems utilize an quartz sand filter, active carbon filter, softener, PP filter for the pretreatment of raw water. The pretreatment process not only removes order, color and some bacteria, but protects the RO membrane as well, which helps to prolong the life of the RO water treatment equipment and is the main function of the pure water treatment equipment.