Cov dej kho dej tau muab faib ua cation resin thiab anion resin, cation resin ntxiv subdivided rau hauv sodium hom thiab hydrogen hom, sodium hom resin pauv calcium thiab magnesium ions hauv dej rau hauv sodium ions kom muag dej. Hydrogen resin yog los pauv calcium thiab magnesium ions hauv dej rau hauv hydrogen ions kom muag dej. Anion resin muaj cov hydroxide ions hloov tau, uas tuaj yeem hloov cov kua qaub ions hauv dej. Nyob rau tib lub sijhawm, kev siv cov anion resin thiab hydrogen cation resin tuaj yeem ua rau cov dej muag muag. Dej ua dej ntshiab.
