I have been filtering my water and these work great.  I used to get ReadyRefresh deliver two 5 gallon a month but they increased their prices and I decided to try this.  Our water in Indianapolis IN is very bad. I checked it this morning and it is at 601.  The filter brings it down to zero for about 4 days and then it starts to go up a bit.  I usually change the filters after about 20 days or when it gets around the 22 mark.  I only filter water for making coffee and tea.  Highly recommend.  And I like the autoship.