Please visit the following sites you will find the answers to your questions. http://www.ianr.unl.edu/PUBS/water/g1275.htm http://www.ianr.unl.edu/PUBS/water/g1280.htm
Have your water softener serviced by a professional to make sure it is working effectively. I would recommend a reverse osmosis system for your drinking water
You will be adding some additional treatment to your system.
Respectfully David F. Walling