Low Alkalinity Water (Low TDS)

[PeeBee]

My Water Company (Dwr Cymru) snuck this update past me (no idea how long they published it, wasn't there last October, but I've got it now):

Water Report (Brief) 2014 B06 - Denbigh Zone.jpg (141.4 KiB) Viewed 332 times

Everything appears to have crept upwards, and there's some unwelcome hiccups in it!

First off: Comparing it with the earlier version:

82093-1680718820877_WEB.jpg (22.08 KiB) Viewed 332 times

I'd always moaned that having low alkalinity water isn't the dream water most think of, and this "update illustrates it well.

Before going there I'll get this saved ...

[PeeBee]

Note neither have a Calcium figure (mg/l). I take this to be because they test for arcane "Hardness" and calculate the Calcium figure from that. Hence, they do a Magnesium analysis so they can separate Calcium from "Hardness": Note they can also quote Calcium and Magnesium in their "Hardness" guises ("as CaCO3").

I also had this water tested by Neil at Phoenix Analytical last October:

Much the same, but notice the big drop in Alkalinity. (There's a big rise in Sulphate too, but that's within the range in the main Report, it only looks big because of the magnitudes reported; 10mg/l difference isn't really very much at all). It is reasoning out that Alkalinity "drop" that is the main purpose of this thread ...

[PeeBee]

So, I'll analyse the latest analysis first ... And yes, this is an excuse to air my "Defuddler" spreadsheet:

Defuddler - 2014 B06.jpg (91.99 KiB) Viewed 326 times

The Calcium box is grey because the figure was derived from the "Foetid Mire" (all the "Hardness" stuff lurks down their). The values the "Foetid Mire" uses or calculates hang about the interface between the Mire and the top boxes (surface); values from the Mire must be manually transferred with the surface, they're not automatically entered.

Notice the boundary between "Mire" and surface (and the Alkalinity stuff) is all red? This is the "unwelcome hiccups" I mentioned earlier: The Report does not balance ! Shocking! What are Dwr Cymru up to ...



[Suspense! It'll have to wait for another day (probably while I figure it out too).]

[PeeBee]

continued...

Previous Dwr Cymru water reports had been okay (had "balanced"), but not this new collection! What I'm guessing is the main report and "summary report" has gotten uncoordinated. The main report was made up of a specified number of tests published as the "average" and "high" value for each substance/parameter tested. Obviously too much detail for the "summary report" in which the numbers are just single values, picked out from what may be (or may not be) a range of sample tests. The "summary tests" are mainly "Water Hardness" results although the report shares some compounds used in the main report (e.g. "Sodium mg/l"). But there's no obvious link of what is shared between the reports, and therefore there may be no link between groups of values in the same report?

Blah! Over-complicated drivel. I'm just wanting to imagine some reasons for the reports not sharing the same values. And therefore, a value of "Alkalinity" may be from a different time than values for, "Magnesium" say, and combined with low values for substances within the water, the reported numbers readily get unbalanced? Argg! More driveling.

But whatever, I need better Alkalinity values.

I could use test kits: The popular kit is the Salifert "KH/Alk", but last time I looked it had changed and was only valid for Alkalinity levels over 300ppm as CaCO3. But more recently there are suggestions it changed back (Amazon are showing the "three bottle kit" again?). But that's not for now. [EDIT: Silly me! ... it was the "Calcium" kit that changed!!!]

I've got a Hanna Pocket Freshwater Alkalinity Colorimeter Checker (ooh, flashy! ... I flippin' hope so, 'cos it cost more than enough).

20240322_133902_WEB.jpg (58.46 KiB) Viewed 263 times

"15" (ppm as CaCO3). Better, but still doesn't balance. I'll try Neil's (Phoenix Analytical) report ... That works! And if I add back Dwr Cymru's repot for "Nitrates" (for balance only, Neil's report suggests none) ... now it doesn't balance! Well, I know what Neil would tell me for "modifying" his results! Me ears are still sore for having them clipped for previous misdemeanours in Neil's field, so "Nitrates" get dumped again. The "Nitrates" accounted for 2.6ppm of miscellaneous "balancing" ions, which illustrates how fussy I'm being! I reckon this concentrating on irrelevant detail is probably common amongst people with next to nowt in the water. I'll keep a diary of "Alkalinity" results for the next few weeks to see if anything crops up.


So! I've got a balancing report ... but it has done nothing to explain the low mash pHs I get . Back to the drawing board ... (I need a bigger drawing board).

[PeeBee]

... Blah! Over-complicated drivel. ...

Except it wasn't, or my blasé attitude was not noticing a little issue creeping into my "Defuddler" spreadsheet. If I'm relying on five items to check the validity of a sixth, I don't want any of them to change willy-nilly. Yet I allow it, even encouraging it, to happen!

While I fix it, avoid the "Defuddler" for anything other than straight-forward "vanilla" queries. I'll have it fixed in a jif... a little while.

[PeeBee]

I reckon I have the culprit (well, the culprit was me ... I reckon I have the issue):

The issue that cropped up is due to the unlikely (imaginary?) connection between "Alkalinity" and "Total Dissolved Solids". I was adding up the major ions (as anions and cations in mEq/L units, but not any "as" bicarbonate), subtracting the anions from the cations, and declaring the difference to be "bicarbonate". Which is reasonable, provided you don't want to change the "Alkalinity" figure.

Most enter values from a single report, have no reason to fiddle with the "Alkalinity" figure, never unknowingly engage the "ion-mass" balancing mechanism, and therefore never see the issue. Yet I'm intentionally messing with the "Alkalinity", dragging ion values from various sources, and running headlong into the issue. ... The issue: I can't change the value for bicarbonate without making a corresponding change to the cations ("metal" ions). Should put an end to my calcium figure seemingly increasing in value as I reduce the bicarbonate value.

I'll fix some miscellaneous issues while about it, like instruction updates.

[PeeBee]

This I just found sort of describes what I was doing:

Alkalinity, TA
The total alkalinity (TA) of seawater may be defined as the charge difference between the major conservative (concentration unaffected by changes in pH, pressure, or temperature) cations and anions:

TA = ∑conservation-cations - ∑conservation-anions

From S. Barker, in Reference Module in Earth Systems and Environmental Sciences, 2016 ... hence the reference to "seawater"!

Blah, blah. But a useful reference to show I wasn't making it up ... but I was making changes to the "TA" bit without corresponding changes to my "conservation-cations/anions" (the "not carbonate or bicarbonate stuff").

That waffle is to make me sound clever while admitting a daft mistake.

I've updated my "Defuddler" spreadsheet to less easily make such a mistake and called it "Puddleduck mode". It has reverted to a less adaptable tool. A new sheet in the spreadsheet will be given the name "Bogsnorkler mode" and contain all the adaptability (like customisable Alkalinity), but the actual sheet will be added at a later date. I'll have deleted some references to altering "balance" with "ppm" as I never actually finished it (mass-balancing with mEq/L values only now ... it's stuff "under-the-hood"). Splitting the "versions" like this makes for a less complex final spreadsheet (which equals less work for me).

Most (if not all) those who have tried the "Defuddler" have effectively only used it in "Puddleduck mode" anyway? "Bogsnorkler mode" is targeted mainly at brewers with low dissolved solids in their water (like me!). Most folk put up with high dissolved solids.

I'll update the downloads shortly.