The filter element for water purification has a service life. The pre-PP cotton needs to be replaced as soon as 1-3 months, the activated carbon needs to be replaced as soon as one year. The service life of RO membrane is about 2 years. For places with poor water quality, the better frequency is higher. The filter element of the water purifier is used to block impurities in the water. After a long time of interception, more and more impurities are attached to its surface, which will affect the passage of water. At the same time, the accumulation of impurities will also accumulate more bacteria, making our water purification can not play the role of purification, but the water becomes more dirty. Therefore, the water purifier can replace the filter element in advance, but not later. Moreover, the current water purifier has the function of reminding the water purifier to change, which can be the faucet, the alarm of the water purifier host, or the intelligent APP reminder.