... medium quartz sand filters, main purpose is to remove the water contains sediment, manganese, rust, colloid material, mechanical impurities, ... organic material, adsorption of residual chlorine in the water, using water more than less than or equal to chlorine 0 ... (Resin softener)Cationic resin used for water softening, primarily to remove hardness of water. The hardness of water is a major calcium (Ca2 ...