There are two categories of general household water purifiers: one is ultrafiltration machine, whose main function is to remove sediment, rust, bacteria, suspended solids, algae, macromolecular organic matter and other harmful substances that may be contained in water, and to retain minerals that are beneficial to human body. Therefore, it is a normal phenomenon that there will be scale in the burned water in the area with serious scale. Another main function of the water purifier is to filter out the rust, sand, colloid and other harmful substances in the water, and at the same time, it can absorb the heavy metal substances such as viruses and bacteria in the water. Very poor water quality can also become direct drinking water.