Magnesium and calcium ions present in the water are responsible for the degree of hardness of the water. Their compounds with carbonates are also referred to as lime. At higher temperatures (higher than 60 ° C) they form insoluble compounds, which are noticeable in the form of calcium deposits. These deposits are deposited in equipment (coffee machines, kettles, pots, rice cookers, etc.) and affect the enjoyment of tea and coffee.
The removal of calcium and magnesium softens the water and prevents the insoluble compounds. The taste of tea or coffee can fully develop!
Water filters (reverse osmosis systems) can remove the interfering ions. Widely used, however, and proven for a long time, are ion exchangers. Ion exchangers are substances that contain sodium ions in the unused state. If lime-containing water is allowed to flow through such an ion exchanger, the magnesium and calcium ions are bound in the exchanger and exchanged for the sodium ions.
Such treated water remains clear until boiling and no disturbing precipitation can form.