Simply fill the input water tank with plain tap water and choose between still, medium, or high carbonation. After starting a dispense, the water will run through the Mitte Home Cartridge to be mineralized before being filtered by a layer of activated carbon and a hollow fiber membrane. The microminerals remain in the water throughout the filtration process as the particles are too small to be filtered out. The water will then be dispensed into the bottle. If you select still water, it is ready to be enjoyed. If you choose carbonated water, it is then injected with CO2.