Where does this come from, and can I check it?

Hard water runs through resin beads that swap hardness minerals for salt. The figure is taken from US Geological Survey, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a everyday life fact?

Yes. It sits on the Everyday Life shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

Mondo Knows Facts

Water softeners trade calcium ions for sodium ions

Hard water runs through resin beads that swap hardness minerals for salt Hard water carries dissolved calcium and magnesium, which form scale and stop soap lathering. In a softener the water passes a bed of resin beads loaded with sodium ions, and the beads prefer the doubly charged calcium and magnesium, releasing sodium in exchange. A brine rinse later washes the caught minerals away and recharges the resin. It sits in Mondo's everyday life collection, one of 200 facts that each trace back to the reference below.

Where this comes from

US Geological Survey

Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.

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Tags: water, chemistry, plumbing

Water softeners trade calcium ions for sodium ions: the short answers

Where does this come from, and can I check it?: Hard water runs through resin beads that swap hardness minerals for salt. The figure is taken from US Geological Survey, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a everyday life fact?: Yes. It sits on the Everyday Life shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.