We have been using the Cerra system for several months now. The filter gave us very alkaline water, with a great taste. rnWe have softened well water and we were informed before our purchase that the filter may not work as efficiently as it would on city or bottled water. Likely due to the extra filtration needed for well water, the filter didn't remain effective for as long a time as advertised. rnThe main issue we had with the water was its superior alkalinity. My husband and I are both in our 70's and the added minerals (probably the magnesium) had quite the laxative effect on our bowels, even though we very gradually incorporated the filtered water. We have had to greatly reduce our intake in order to maintain proper bowel function.rnTo sum it up, the filter works really well. For personal reasons, we can only use it sparingly.rn