Ion exchange can consistently remove hardness from water to extremely low levels. Softening removes dissolved iron and manganese. Other water quality factors such as pH, alkalinity and dissolved oxygen are not critical to removing iron and manganese. Conventional softening also removes dissolved radium. The process is equally as efficient however the cost of potassium chloride is higher than sodium chloride Softening will not operate satisfactorily if iron bacteria, clay particles, rusty colored water etc. exists, even occasionally.
Water softeners require a location to disposal of waste brine.
If you do not have sewer service, disposal of the waste brine will likely be into the ground. This creates the potential of contaminating the groundwater and subsequently your own well or those wells of your neighbors down hill. If potassium chloride is used the potassium is also a soil nutrient being one of the three components of typical fertilizer. Consequently reducing salt usage while maintaining system effectiveness, is important. In areas without sewers, the more reduction of salt, the more appropriate is water softening treatment.