Magic to turn hard water into soft water
Soap does not dissolve well in hard water. On the other hand, soap is well solved in soft water.
This is because hard water contains calcium ions(Ca2+) or magnesium ions(Mg2+). Ions dissolved in hard water inside the boiler tube can also create fouling.
Ion exchange resins convert calcium ions or magnesium ions to sodium ions(Na+).
Besides, there are various kinds of ion exchange resin.
If the ion exchange resin is used for a long time, its performance may be degraded and need to be replaced.