Due to the different water quality in different places, the service life of the Water Filter Cartridges(KOKOELECTRIC) https://www.kokoelectric.com/product/water-filter-cartridges/ is also different. However, no matter how long the service period is, it is only a matter of time before the water filter cartridges are replaced. The following three situations indicate that the water filter cartridges need to be replaced. First, the water produced by the water purifier becomes smaller. Under the same conditions, the water produced by the water purifier becomes less, so it is very likely that the water filter cartridges are blocked, a large amount of sediment in the water will block the water filter cartridges, or the water filter cartridges of the water purifier is close to its service life, so it is necessary to replace the water filter cartridges with a new one. Second, the taste of the water from the purifier is poor. This kind of situation occurs because there are too many impurities and bacteria filtered by the water filter cartridges of the water purifier, and the accumulated time at the water filter cartridges is too long, resulting in secondary pollution to natural water. This tells us that we need to replace the water filter cartridges. Third, the water purifier is estimated to have reached 80% of the service life of the water filter cartridges according to time. The service life of the water filter cartridges is the ideal service life of the water filter cartridges of the water purifier. The water quality in each area is different, resulting in the different service life of the water filter cartridges. For example, in areas with poor water quality, the replacement time of the water filter cartridges will be shorter, but in areas with better water quality, the replacement time can be longer appropriately. We do not recommend that the water filter cartridges of the water purifier be replaced only when the ideal life is reached. It is better to replace the water filter cartridges at about 80% of the ideal life, so as to better protect our drinking water health. If you are interested in our products, you can click Water Dispenser With Filtration https://www.kokoelectric.com/product/water-dispenser-with-filtration/ to learn more information.