The naturally occuring minerals and chemicals found in tap water can build-up inside your coffee machine, causing premature breakdown and a bad tasting coffee. The De'Longhi BPA-free Water Filter significantly reduces the likelihood of premature breakdown from scale build-up which in turn improves the machine's performance, keeping a consistent brew temperature and flavor. It's internal active carbon and ion-exchange technology traps unwanted chemicals and aromas, optimizing water to give you a better in-cup experience. Using De'Longhi's BPA-free Water Filter Replacement will also decrease the need of descaling by 20%