I appreciate this thread has pretty much died now, but I thought I'd revive it after spending some time looking into water softeners. To be honest, my initial impression was that Polly was being treated a little harshly and was somewhat "ganged up" against, but I'm no longer so sure...
I don't understand the chemistry in detail, but I thought there might be something in Halcyon's claims after reading testimonials. We must remember that the absence of proof doesn't mean something doesn't work - it can be very difficult to prove certain things (with a background in health, I appreciate that not everything is as simple as comparing two pills in a placebo controlled trial).
However, I've since come across two things :
1. Polly's LinkedIn profile which seems to suggest that her "scientific background" consists of an A Level in Chemistry (so not much)
2. This PDF which clearly states on page 12 that Halcyon softens water: http://constructingexcellence.org.uk/wp-content/uploads/2017/05/BRE-Sustainability-presentation.pdf
So whilst I didn't think it was worth splitting hairs when Polly stated that the company doesn't advertise (it was pointed out that having a website is indeed advertising, but I knew what she meant), this clearly isn't true. This PDF is indeed advertising and I know that Halcyon have attended various events over the last few months, not to mention their regular updates to their social media feeds. So let's be clear, they do advertise and their literature still claims that they soften water.
Unfortunately Polly no longer works for Halcyon, so I'm not sure if we can expect any further update from them. For example, it would be good to know the outcome of the trial she mentioned that was about to be conducted with a university.
Without that, am I right in saying that observers such as JSHarris are convinced that Halcyon's claims are complete nonsense? Or would you not go that far? Are they at best possible, but unlikely to last more than a few seconds/minutes? I'm trying to gauge if there's any value in researching this further. I'm certainly not going to spend several hundred pounds on a tube of metal that effectively does nothing!
Doesn't that just apply to AG2/AG3 environments, as in the overarching section 522.6 above it, though?
A domestic installation isn't likely to be either an AG2 or AG3 mechanical impact environment IMHO.