After using a Reverse Osmosis system for years I learned that was depriving me of vital minerals. Not wanting to drink our softened well water, I decided to try Berkley. I bought the little travel one because my kitchen is small and has limited counter space, and there are only 2 of us in the household. Running softened water through the Berkley is not recommended so I use water straight from the well (which I never would have dreamed of drinking unfiltered). Once it's been through the Berkley it tastes great, and I feel better knowing I am getting the minerals I need. Because our well water is on the hard side I have to clean the black filter every few weeks and re-prime, but it's worth the effort. I like my Berkley water so much I bought a larger unit for my son and his family.