Replace your PiMag® water system filters and components regularly for optimum performance. We recommend replacing the filter every 90 days. Mineral stones can be replaced annually. PiMag® Aqua Pour®: Gravity Filter cartridge: 6 months or 528 gallons (2,000 liters), whichever comes first* Gravity Micro Sponge Pre-filter: 5 years or 5,283 gallons (20,000 liters), whichever comes first* Gravity Ceramic Pre-filter: 2 years or 2,113 gallons (8,000 liters), whichever comes first* Gravity Mineral Stones: 1 year or 1,056 gallons (4,000 liters), whichever comes first* *Component life may vary, depending on water quality