Dealkalization process for reducing hardness in a water without adding sodium is accomplished with a weak acid cation exchanger in the hydrogen form which converts hardness associated with alkalinity to carbon dioxide and water. The water is then put over a degassifier to remove CO2. A softener then removes any permanent hardness remaining in the effluent of the degasser. After degasser small amount of caustic may have to be fed to increase the pH level of degassed water.

2 R-COOH + Ca(HCO₃)₂    ―>    R₂-Ca + 2 H₂O+ 2 CO₂     Service

   R₂-Ca + 2 H⁺                      ―> 2 R -H + Ca⁺²                   Regeneration