Ion Exchange Resins Cationic Softening Resins (Na+) It is used in softening systems. It is suitable for food. Grain size is 0.3-1.2 mm. Cationic Resins (H+) It is used in demineralization systems. Anionic Resins (OH-) It is used in demineralization systems. Mix Bed Resins They are resins used to obtain high purity demineralized water.