We use acid ion exchange resin for water filter. It is widely used in water purification and decontamination processes. It has chemical reaction with calcium and magnesium ions.
The resin exchange the calcium and magnesium ion ( Ca2+, Ma2+) in the water and therefore, the water is softened/demineralized.
TIP: After Using for 2-3 months, depending on the hardness of the local water, it's water softening function will get weak. To re-active the filter, users could soak the filter in in 5% salty water for 24 hours and dry it cool, then the filter can be reactivated. After 2-3 times reusing, it's water soften ability will get weak. then you need to replace it, so the water filter is actually a consumable accessory.
TIP 2: Applicable Model: