The water supply in our apartment is hard water and is not suitable for daily use like washing clothes, drinking, bathing etc.

Are there water purifiers we can put on the main water pipe which goes into our house? How sustainable are they?

1 Answer 1


There is only one effective measure, and that's an ion-exchange water-softener.

The good news is that the major inputs are sustainable, or potentially sustainable: electricity, and salt. Similarly, the waste product, calcium chloride, has no (to my knowledge) negative ecological impact on being added to waste-water streams.

As for the catalyst itself, I don't know about its sustainability. On the positive side, it does last for years.

The casing is recyclable plastic.

The electronics (if present) should on disposal be treated as electronic waste, and can be processed to extract reusable materials.

  • ^ This. However, since OP also mentioned "drinking", be aware that an ion-exchanger will replace calcium with potassium. Negative effects from calcium in water are pretty much unknown whereas increased potassium supply is known to negatively affect blood pressure (and with present day foods, it's already very hard to only consume twice the daily allowance of potassium, most people consume 4-5 times as much). I'm not sure if (apart from reverse osmosis which is crazy expensive, or well, distillation) there exists a way of reducing calcium without adding potassion, though...
    – Damon
    Jun 23, 2015 at 11:20
  • 1
    @Damon I've only ever seen sodium ion-exchangers. Potassium ion-exchangers may well exist too, but I'd have thought that sodium salts are much cheaper and more readily available than potassium salts.
    – 410 gone
    Jun 23, 2015 at 13:06
  • My bad! I meant to say "sodium" (= natrium). I always get them alkali metals mixed up since they have grossly different and unintuitive in English (which isn't my native language).
    – Damon
    Jun 23, 2015 at 13:15

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