Charcoal water filter removes impurities: chlorine, calcium, bad tastes and odors Great tasting water makes great tasting coffee Each filter individually bagged and sealed to ensure brand new quality. We recommends changing the water filter every 60 days or 60 uses, mo re often if you have hard water Size:10 Filters Coffee is 98 percent water. Often overlooked, the quality of the water is as important as the quality of the coffee. A good rule of thumb is that if your water doesn't taste good from the tap, it won't taste any better in your coffee. That's why we suggests adding a water filter to the coffeemaker. The charcoal water filter removes chlorine, calcium, bad tastes and odors, for the purest cup of coffee every time. For use with all Cuisinart models.