Fighting Limescale: Is There a Science Behind It?

[sophiecentaur]

Some while ago, I posted this topic on another forum (elsewhere) and was greeted with much skepticism and disbelief. I was not surprised and would have taken this view if it were not for personal experience.

There are a lot of products available for fitting to the incoming water supply which are claimed to reduce limescale. The seem to be based on permanent magnets or electromagnets which are pulsed.

I live in Brighton - a very chalky area - and my taps and heater elements used to accumulate a very hard limescale deposit. This was particularly noticeable on the underside of taps, where a very hard 'stalactite' would form. It was so hard that you needed a knife to scrape it off. Kettle elements used to build up a thick hard layer very quickly.
Several years ago I fitted one of the 'electronic' versions, which involved wrapping a coil of (about 100 turns of) wire around the rising main. There was no dramatic change but I soon found that the electric kettle now seems to shed its scale and you can empty most of it out after sloshing water round it and the taps, having cleaned them off once, just need a mild scraping with a fingernail to remove the scale buildup. I couldn't say that there is less scale but its nature has definitely changed.

There is no need to introduce the topics of double blind tests and objective measurement methods into this thread because, of course, that is the only way to treat the subject properly but I have no such evidence.
BUT i should really like to know if informed opinions have changed significantly about the subject and are there any worthwhile theories to explain or justify my experience. Many plumbers 'swear by them' which is some sort of evidence, I guess and I have read the instructions for installing one form of solar heating which expressly discourage the use of this form of scale preventer as the particles can clog narrow pipes.

I really don't need to be told that it just isn't happening because X,Y or Z is true. If it's a placebo effect then how can that be affecting what we 'see'?
I feel a bit awkward about posting this as I have made some pretty devastating comments about other ' alternative' Science claims but I have seen something happen and would love to hear an explanation.

 

[chemisttree]

I've heard that this causes the scale to form in the water rather than on surfaces. It could be true since there are http://www.lsbu.ac.uk/water/magnetic.html"

I don't think it helps with soap scum and water spotting so well although I suppose that some might say that the water spots might be more friable and easy to remove.

 

[alxm]

If you don't want people to tell you that these products are a sham, that they do not work, and they cannot possibly work through any known science at all, then you shouldn't be posting that in the chemistry part of this board. Because that's just how it is. If a simple magnet would affect chemistry to that extent, we'd have known about it centuries ago. Whereas our understanding is that magnetic fields hardly affect chemistry at all. And that's an 'experiment' being done thousands of times a day in positively gigantic magnetic fields in NMR and MRI machines, with no measured chemical or physiological effects.

'Seeing' something that's not there, is a very common phenomenon. If you want to understand how psychological suggestion works, how expectations shape your perception of things, and how http://en.wikipedia.org/wiki/Confirmation_bias" works, then you should probably be asking in a psychology forum.

Read your own post! You're in effect saying "I want to hear how my preconception could possibly be justified scientifically, but I don't want to be told that I'm wrong". That's confirmation bias.

There are two explanations for your thing: Either it's a new, completely unknown chemical effect that somehow have gone undetected for centuries of playing with magnets and decades of playing with gigantic magnetic fields, and despite that there's almost nothing we understand more accurately in physics than how magnetic and electric fields interact with matter on the atomic and molecular level.

Or: It's an old, very well-known, common psychological phenomenon. And not even a particularly extreme example of it. Just look at the stuff people in religious cults can convince themselves of.

 

[chemisttree]

If you don't want people to tell you that these products are a sham, that they do not work, and they cannot possibly work through any known science at all, then you shouldn't be posting that in the chemistry part of this board. Because that's just how it is. If a simple magnet would affect chemistry to that extent, we'd have known about it centuries ago. Whereas our understanding is that magnetic fields hardly affect chemistry at all. And that's an 'experiment' being done thousands of times a day in positively gigantic magnetic fields in NMR and MRI machines, with no measured chemical or physiological effects.

Hold on, Sport! Are you saying that magnetism has no measured chemical or physiological effects? Do a bit of research and you will be suprised, I think.

Try http://cat.inist.fr/?aModele=afficheN&cpsidt=4240476".

I don't think they are all delusional and so I keep an open mind.

 

[sophiecentaur]

@alxm
I take your point but the difference I have found is not just subjective. I was, perhaps, a bit too tentative for my own good(!) in my post.

I had no "preconception" except that I had heard several recommendations and though it worth giving it a go. Yes - I had invested some money in the device but I was quite prepared for it not to show an effect. I would have been just as pleased to be able to say "It's all a load of rubbish". The difference in hardness of the limescale is about as objective an observation as one could make. It used to need a knife to remove and now it comes off with a fingernail.
Perhaps I should be asking for an explanation of that, rather than submitting my mind for examination.

Interestingly, my main 'antagonist' in the last thread about this was also a Chemist who dismissed it as not worth thinking about and, as a Physicist / Engineer, I have often given people a hard time when they have posted dodgy ideas in those fields. BUT, when someone asks for an explanation, one doesn't want to be told that it just didn't happen.

I would be interested to hear from someone who has actual experience of the quantitative (temporary) effect of magnetic fields on crystal growth. axlm, have you actually any experience in this field or is it just that it seems so unlikely that you can't believe there's anything in this? How many of your quoted 'experiments' have actually looked for this particular effect? Anything involving water would almost certainly use the de-ionised variety to avoid unwanted factors.

Remember, they laughed when Matt Lucas said he was going to be a comedian. They're not laughing now.

I did, actually, talk to a technician who was involved in a superficial study in a lab in London of this and it did appear to have some basis.

@chemistree
Thanks, I read the link but could be a bit too general to be relied upon, I think. It also appears to give some credence to homeopathic chemistry and that rings alarm bells with me. It is full of references, though, so it may well be ok.

 

[sophiecentaur]

Thanks for the other list, chemistree.
So I may not be a raving loony after all!?
What a relief.