Given that the total dissolved solids (TDS) in water and its hardness decrease the quality of potable water as well as problems such as corrosion, scaling in pipelines and imposing enormous costs, comprehensive research on various methods for reducing the TDS and hardness is vital. However, in terms of industrial or potable water, finding effective and economical absorbers to reduce water hardness and TDS is essential. In this study, the various methods using for improvement of water quality and reduction of TDS, especially methods of various ion exchange resins are presented. Such studies can be useful in implementing Water purification technology to gain healthy and suitable potable water as well as decrease time and expenses.