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🪨Hard water vs Soft water💧

Water hardness depends on dissolved mineral ions. The amount of calcium and magnesium decides whether water is hard or soft.

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🪨Hard water
  • High in calcium and magnesium ions
  • Forms scum with soap
  • Leaves limescale in kettles and pipes
  • Lathers poorly with soap
  • Often from chalk or limestone areas
💧Soft water
  • Low in calcium and magnesium ions
  • Lathers easily with soap
  • Leaves little or no limescale
  • Found in areas with hard rock like granite
  • Can be produced by ion-exchange softening

Verdict

Hard water carries dissolved calcium and magnesium that fight soap and form limescale; soft water has few such ions and lathers easily. Hardness reflects the local geology.

Frequently asked

What causes water hardness?+

Dissolved calcium and magnesium ions, usually picked up from chalk or limestone rock.

Why does hard water form limescale?+

Heating it deposits insoluble calcium carbonate as scale in kettles and pipes.

How is hard water softened?+

By ion exchange, swapping calcium and magnesium ions for sodium ions.

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