As a realtor I see a lot of homes and different water systems. I held an open house for a client and filled up my Yeti with ice and water from their refrigerator. Once my ice melted I could tell the difference as there was no residue in the water. (I live in the same neighborhood with no system). My clients sold their home and purchased another for their new home. They swore by it. So, after some nudging to my husband, we set the appointment and were able to have our system installed in just a few days. My husband said he could tell the difference immediately. A few weeks later I went to my daughters and filled up from her refrigerator water. WOW, I sure could tell what we're missing and I like it! We are super happy with the system.