The majority of maintenance a water softener will need is salt replacement. Most customers are able to replace their own salt with relative ease. Water softener salt will cost between $40 and $70 a year.Other common water softener problems are easily diagnosable and usually can be fixed by the homeowner. Read here for common water softener issues and how to fix them.For reverse osmosis systems, the filter will need to be changed annually. Some homeowners do this on their own but Clear Water Concepts can change your filter for you.