Colin Solves Your Problems 18: Hard Water and Calgon

I get some strange questions on here sometimes.  Here’s one from Maria.

 You said we could ask anything, not necessarily related to the cosmetics industry. I live in a very hard water area and my washing machine heating element gave up the ghost recently. On inspection, it was covered in a rather nasty, hard, discoloured substance which I took to be limescale.

My new machine has arrived and I want to avoid this happening again, so I have decided to use Calgon. However, this will be pretty expensive if used in each wash so my question is (1) is a softener necessary with each load and (2) is there a simple chemical substitute or other commercial product that I could use safely?

What an interesting question. I used to live in Eastbourne where the water comes straight out of the chalk hills of the Downs. The water there is as hard as it is possible to be. I remember very well that electric kettles used to fur up in no time at all. I also maintain that you get a much better cup of tea from hard water. But I don’t remember ever having any trouble with washing machines.

So I had a look at the chemicals in Calgon, and sure enough they should stop calcium salts forming and so ought to be beneficial to the life of washing machines. But I was puzzled as to why nobody in Eastbourne ever complained about it.

So I had a chat with someone who knows about washing machines who told me that they are designed so as to avoid scaling of the elements. That was fair enough, but even so there must be some deposition I thought, but I don’t ever remember seeing any sign of it at all in a washing machine. Kettles, yes. Baths, yes. It even showed up on the ends of taps.

So I had a look at what goes into laundry detergents. And there was the answer. Laundry detergents already contain phosphates and zeolites. Mystery solved. As I am a bit of a greenie I sometimes wash things that aren’t especially dirty without detergent. I think I am going to get hold of some Calgon for when I do that. But it is probably not going to give much if any benefit if you are already using detergent.

I hope this is helpful, and thanks for provoking my thoughts. I haven’t decided whether or not to run this as a bog post or not. It is interesting but I think it might be a bit too off topic.



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3 thoughts on “Colin Solves Your Problems 18: Hard Water and Calgon

  1. JP

    Colin and Maria

    I think I might be able to shed some light on this one. I’m an expat living in rural Canada who also owns a bath and body manufacturing business. Our home only has electricity as an outside resource, no mains water, gas or sewer. Our water comes from our own 120′ deep well into limestone so the water is really hard. Advice from the local appliances repair company is washing machines are not affected, don’t bother spending money on fixes for a problem that doesn’t exist.

    Add a cup full of citric acid to the dishwasher every couple of weeks, far cheaper and just as effective as any of the dishwasher cleaners you can buy. You can get citric acid quite cheaply from anywhere that stocks bath bomb making supplies.

    For the kettle mix up half a cup of vinegar in a full kettle of water, bring to boil and leave for a couple of hours. We have never had any problems with water pipes furring up, we do not use a water softener and soap scum is easily cleaned up with a decent bathroom cleaner. We use a U.V. sterilizing light to kill any pathogens that might be present. Bottled and city water tastes absolutely disgusting after drinking good quality well water. Oh, and we use distilled water in the manufacture of all our products because you just never know…..

    Hope that helps
    Thanks for a great blog Colin

  2. David Bradley

    Offtopic, but interesting nevertheless. Perhaps you could add a little bit of expo for your non-chemist readers to explain what phosphates and zeolites are and how they chelate and/or adbsorb hard-water ions…

    There is another point though. Washing machines don’t tend to run at high temp these days, it’s heating water strongly (i.e. boiling it) that leads to precipitation of calcium and magnesium salts, which deposit on surfaces within a kettle or steam iron.

  3. midnightz

    Limescale is less likely to form where there is a lot of agitation so that’s why it is less obvious at first inspection in a washing machine. If you were to remove the drum and look at the pipes then I expect you’d see where the build up is happening, especially on the heating elements.

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