Ingredients & DescriptionOn average, the filter will last about one year. Initially, the filter will remove 98% of the chlorine. Over time, the removal percentage declines until it is at about 87% after one year. Accordingly, we recommend annual cartridge replacement. To make it easier to change the filter, we recommend soaking the entire unit in hot water (1 gallon) and white vinegar (1 tablespoon) for about 10-15 min. Take the unit out while it is still hot and turn it counter-clockwise.