So far it has worked very well. I have had it in our toliet for a month now and it has passed the 5 Star test.
There is some improvement in the Well water residue in my toilet. I would encourage people to very thoroughly clean their toilet and the back tank, which I had never cleaned before. I hope that gives this method a chance to keep up with hard water residue in Colorado well water.
Have seen some results but haven't seen all the stains be eliminated