Just bought a Samsung refrigerator .  Ran over a gallon of water through the system.  I tested the water from the fridge and got 154 PPM.  I tested the water from the tap and it was 171 PPM. Apparently it doesn’t filter out a lot of chemicals.  I had a Zero Water that I discarded because the fridge had a filter.  That was a mistake.  There is no listing of the filter’s efficacy.  I wonder why!  Will have to install a filtration system prior to connecting to the fridge.