I want to write the piece I could not find when I started looking into this, which is one that treats the reader as capable of holding two different levels of certainty at the same time.

Almost everything published about water devices comes in one of two flavours. Either it is selling you something and every claim arrives at the same confidence level, or it is dismissing the entire category and does not bother to separate the well-understood parts from the speculative ones. Both are lazy, and both leave you unable to evaluate anything.

Filtration removes things. That is the entire concept. Water passes through a medium, and the medium traps or binds particular contaminants — sediment, chlorine, certain metals, certain organic compounds — depending on what the medium is made of.

This is engineering, and it is verifiable in the most ordinary way: you can measure what was in the water before and what is in it after. Different media remove different things, some are better than others, and a filter that is not maintained stops working. None of that is in dispute anywhere.

If your interest in water is about what is in it, filtration is the whole subject and you can stop reading here with my blessing. It is the part I would recommend anybody understand first.

Here the ground changes, and I want to be precise about how.

Structured water devices do not claim to remove anything. The proposition is that the arrangement of the water can be altered — that water passed through a particular geometry comes out organised differently than it went in, while containing exactly the same molecules.

Notice that this is a completely different type of statement from the filtration one. Filtration says: something was in the water and now it is not. You can test that. Structuring says: nothing was added or removed, but the state is different. That is much harder to demonstrate, and it is where the disagreement actually lives.

Two reasons, and the first is simply that it is true.

The second is that I trained as a physician, and a physician who lends his credentials to a claim that has not earned them is doing the most damaging thing available to him. My training is a reason to trust that I know what evidence looks like. It is not a reason to believe a device does anything, and I will not use it that way.

The same applies to stories. People say all sorts of things about how they feel after using these devices, and I have heard plenty of them. Those accounts are not evidence of effect — that is not a technicality, it is the actual reason careful people run trials instead of collecting anecdotes.

What specifically does this remove or change, and how would that be measured?
Is the mechanism you are describing settled, or is it a proposal?
What does the device physically consist of, and why that construction?
What will you not claim about it?

That last one is the most useful question in the category, and the answer tells you more about the seller than the first three combined.

This is a preventive orientation and it does not compete with the medical system. Nothing here is intended to diagnose, treat, cure or prevent anything, and nothing here should replace care from your own physician — whatever you decide about any of it, do not neglect your traditional medical treatment.

My goal is to inform, not to push. If that leaves you deciding this is not for you, that is a perfectly good outcome and it means the writing worked.

And if you think I have got any of this wrong, say so in the group. Sceptical questions are the ones I most want.