Drink tap water, nothing more economical. It is also necessary that the unpleasant odor of bleach is dissipated and the limestone is done less present especially for coffee pots and kettles other, a very well filled by Brita filter role. Batch 2 makes biannual operation since each filter has a life span of about 3 months for a daily consumption of 4 persons. I could found. The replacement of the filter on the Brita On Tap is easy, a little guide is inside each box, the manipulation takes less than 2 minutes.