In general, when the standardized flux decreases by 10-15%, or the system desalination rate decreases by 10-15%, or the operating pressure and the pressure difference between sections increase by 10-15%, the RO system should be cleaned. The frequency of cleaning is directly related to the degree of system pretreatment. When SDI15 < 3, the cleaning frequency may be 4 times a year; when SDI15 is around 5, the cleaning frequency may be doubled, but the cleaning frequency depends on the actual situation of each project site.
