Water report Cornwall

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May 9, 2018
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I've been looking at the South west water website and I can see they will lab test your supply for the nominal fee of £75. Before I shell out has anyone else had a water report for mid Cornwall I can take a look at?
If you look at this page you can enter your postcode for a water report.

It might not be as accurate as a full one off test but it'll give you an idea of what's going on.

It'll probably be missing a value for alkalinity, but you can get a test kit just for that for £9 on ebay (item no 401267894949).
Thanks for this. In your experience does this (moderately soft) water look good/appropriate for brewing?
Thank you very much. I have a few brew books and some go into water in some detail. However, I not really paid much attention to those sections...as yet!
The South West Water postcode link is broken...meh... so I'm going to see if a call direct will get me a report.
Thank you very much. I have a few brew books and some go into water in some detail. However, I not really paid much attention to those sections...as yet!
The South West Water postcode link is broken...meh... so I'm going to see if a call direct will get me a report.
No probs. They may even be able to tell you over the phone the values you need, ie. calcium, sulphate, chloride and alkalinity (which they probably won't have but it's worth asking).
Just because you have an accurate water report for a one-off sample doesn't mean that's it. My understanding is that water companies often mix and match their supplies according to demand and availability, including swapping bore hole water for reservoir water and vice versa and buying in water from adjacent companies. So if you really need to know what your water analysis is before you treat it for a brew you really need a testing kit. Any other analysis is only indicative.
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Following this thread with interest. I'm in St Austell and just started researching water treatment.
Excellent! I'm always on the lookout for new, potentially naive, minds to poison. So...

(WARNING: I'm about to wheel out the latest version of my "Defuddler". Some people might prefer to look away now). I've not got this version posted yet; just doing finishing touches to the "documentation" (should post it this week). Always remember the "Defuddler" is a pre-processor: It removes the garbage from water reports and leaves you only with stuff you need to know.

Let's start with the water report @MashBag has posted for the OP. It's perfect! Should make for a good tutorial on the many pitfalls that lie-in-wait within these things. First off, some will say it's missing this and that (like Calcium, Magnesium and even Alkalinity). Then there will be those who invent the most amazing ideas to extract that information. And then there is me! All the most amazing ideas will pale compared to the the "amazing ideas" ideas my (somewhat damaged) head will invent.

First off: You're in Cornwall and like most of West UK will generally have "soft" water (BTW: Neil, at Pheonix Analytical, has been mentioned, and he's going to beat me for mentioning "soft water", but I can take the blows 🤕 ). So, the water won't have very much in it. Next ... out comes the Defuddler. All zeroed, unlocked and awaiting input.


That's the buisness end: Five boxes to fill in plus a little bit of miscellaneous stuff. The first two boxes are greyed as they're not mentioned in the report; they'll be magicked out of the foetid mire, the spreadsheet's repository of confusing and contadictory stuff ... like "Water Hardness"! So, we just need Sodium, Chloride (not "Chlorine"!) and Sulphate from the report. Plug that in:


While about it you can plug in the "Free Chlorine". But it doesn't do owt yet. And you fill in the source (SW Water ...) for future reference. Now the Calcium and Magnesium. Sharpen you senses ... things get a bit weird at this point. In the water report find "Hardness Total as Ca" (near bottom of Page 4): They've been very nice saying "as Ca" because it's normal for this value to depict no units, or just miss out the "as". But, we want the value "as CaCO3", so multiply it by 2.5! Don't worry about it! You'd be mistaken thinking the value means "Ca" for "Calcium" (or "CaCO3" for "Calcium Carbonate") though the symbols can mean that elsewhere. The Magnesium is in that value for starters, and "Calcium Carbonate" (chalk, or limestone) is insoluble in your water!

Lower in the spreadsheet you get to the "Foetid Mire". Here you'll find a box "Total Hardness". The "Ca" and Mg" boxes (Calcium and Magnesium Hardness) get zeroed (amber values) and the box sources changed to "HARDNESS" from "Live Data". The "Total Hardness" box is filled in with the value from the report (which was 9.74mg/l as Ca x 2.5 =24.35mg/l as CaCO3) where-upon ... new values start popping up here, there, every flippin' where. The spreadsheet picks a suitable split to seperate Magnesium from Calcium (ratio of 9:1 works okay for these low Calcium levels, 8:2 for slightly higher levels, and higher still is 7.2:2.8 which someone worked out as the average split of Calcium to Magnesium ... they can be changed if desired).


The "miscellaneous ions" are the NO3 report, There was enough to possibly make a difference to "balancing" and therefore "bicarbonate" which doubles as your "Alkalinity" figure. Don't look for "Hardness", its done its job, and you wouldn't have needed it if the water report hadn't wrapped up useful information in it. And the top lines then looks like:


To be honest, there will be a few folk who'd like their "RO Water" to have mineral values like that.

The "Defuddler" has some features that might be useful here: Low Alkalinity water is often lower still by the time it gets to your house. I'll have a look tomorrow, done enough for now!

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