Water: Calculating Calcium from Hardness & Alkalinity

[RikkiBobbi]

Hi all,

Shameless plea for help in understanding one particular aspect of my water profile in absence of a ppm figure for calcium. I've been meaning to ask this question for ages but, for someone who lives in London, I almost never brew dark beers and so don't use my tap water. (Having just re-read the water treatment for beginners post, it gives a suggested dosage for the bottle of CRS that has been sitting in my cupboard unused for over a year so I could have been using my tap water but always went safety first with Tesco Ashbeck).

Water profile is East Lambeth although the latest report is from 2021!

The profile only gives a figure for Total hardness and alkalinity, both as CaCO3. I've tried to get my head around this before in terms of how to calculate a figure for actual calcium itself but always given up due to brain ache.

The last couple of dark beers I've done (tasted amazing but under attenuated and turned into bottle volcanoes) I've just proceeded blind, treated with salts to adjust Chloride/Sulfate and monitored PH but it feels a bit too gung-ho without knowing the exact water profile.

 

[peebee]

As long as you are not messing about with anything other than (UK?) tap water, you can fill in some apparent gaps. In these circumstances alkalinity is temporary hardness is bicarbonate.

I use "Bru'n Water" much of the time It has its faults (apparently), but it saves a lot of brainwork. Calcium and magnesium make up virtually all permanent hardness (bicarbonate makes up virtually all temporary hardness). This that follows next is making a bigger assumption, but assumptions aren't far off the truth in these circumstances ...

Plug reported Magnesium into the calculator "as CaCO3" ("as CaCO3" was once a convenient way of working with these numbers). I'm using this calculator backwards, plugging in values "as CaCO3" until the "Output" is the same as the reported figure (4.1ppm average). Subtract that from reported "total hardness" ("as CaCO3") (272mg/L = 272ppm) and plug the remainder in for Calcium. The "Output" is roughly the Calcium in ppm.

Plug the reported "alkalinity" ("as CaCO3") and the average pH to get out bicarbonate and carbonate level ("carbonate" will always be very low, zero for many):

Plug this stuff into the main part of the calculator, together with the Sodium, Sulphate, Chloride and maybe some optional inputs:

And ignore the rest of the report. Then away you go. You can check the "ion balance results" if you like ... cor, didn't come out bad!

Even though the report was old data, the readings were fairly stable so you can assume it's still good. I don't necessarily recommend use of Bru'n Water, but many other calculators will offer similar assistance.



Now: Sit back and await the cries of indignation! "That's not complicated enough, you can't do that!".

You flippin' well can!

 

[peebee]

Think I make it up? Well, if I think it's good enough for you, it's good enough for me! My report (Dwr Cymru ... "Welsh Water"):

They haven't updated me yet! Still 2021 data and my report is in flux (they've not 'arf improved it though, like most of what I need is on this "basics" sheet). Note that not getting a proper "Calcium" figure is not unusual!

I do get "Hardness" in "Clark" units. What the hell are they? But I can plug them in the calculator and out pops Calcium at 21.8ppm. <-Err ... WRONG!!! See footnote edit.

Work that 21.8 backwards like the Magnesium in my previous post:

54.3 +5 equals 59.3:

... yikes

phew!



[EDIT: Phew? I knew there was something wrong, but the numbers were playing the game of coincidence with me! Nothing wrong with what I said for @RikkiBobbi, but the figures I've been using for my water calculations are suspect! Converting "Clark Hardness" to Calcium ppm was a bit of naivety from my past. Quite radically wrong too. Explains some of the issues I've been having getting things to add up! Notice it was "Total Hardness" I was attempting to match up? I should have been working with "Permanent Hardness" to match with a Calcium figure (and not the "21.8" nonsense either!). I'll figure it out and post the correction later.]

 

[peebee]

Think I make it up? ...

I probably did! The anxiety and relief at the end of that last post were real! I'd began to realise the reply for @RikkiBobbi was wandering off the track I'd made for myself! But, as long as I'm sticking to the same basic rules, it has to come out right whatever the track.

So, if I outline those basic rules perhaps the thread will have a wider audience?


For water profiling for beer you are interested in the following. Firstly, use tap water as a starting point because:

• You can easily get a profile for the water from the water company's Web site.
• The water should be absent of many weird complicating features.
• The water will be controlled to about pH7.5 where it is easy to make some assumptions.
• You can assume Chlorine is added and easily dealt with.

Secondly, get a reputable water profiling calculator. There are plenty downloadable, on-line, free even. They save an awful lot of brain ache (unless that's what you want, in which case get a supply of pencils, a notepad, a pocket calculator is handy, and a pencil sharpener essential ... and stop reading this!).

You can restrict yourself to knowing:

• Hardness. And/or the Calcium and Magnesium levels.
• Temporary hardness. And/or bicarbonate or alkalinity levels.
• Sodium, Sulphate and Chloride levels.
• Nitrate, Potassium, and a handful of other levels, which are optional and may only help "prove" validity of other figures.

You might have figures in the following units:

• "ppm" or "mg/L" (identical). These are easiest.
• "as CaCO3", an arcane but common measure for "hardness", etc. Has a molar mass of 100g/mol, dead handy when working with pencil and paper (err ... convert or ignore!). Never assume "is CaCO3"! Warning: The "as" is often not printed!
• "meq/L", "mval" and various others. Again, dead handy when working with pencil and paper (err ... again, ignore!).

Other assumptions:

• Hardness is all down to Calcium (mainly) and Magnesium.
• Magnesium is less "hard" than Calcium, and often too small a quantity to include in a report.
• Alkalinity is all due to bicarbonate, as is "temporary hardness" (but the units are often different). Don't get sidetracked by "alkalinity"; it can get horribly involved!

This is your starting point, from which you can build any of the weird and wonderful (perhaps?) profiles. My preceding posts in this thread give examples of wielding the information.


[EDIT: Oops, typo, ml/g instead of mg/L!]

 

[Agentgonzo]

I put everything I leaned about reading water reports in this thread.
https://www.thehomebrewforum.co.uk/threads/how-to-read-a-water-report.99812/
It mentions about converting hardness between HCaCO3 and CaCo3 and CO3, but I think my local water report has a value for calcium in there separate from the hardness/alkalinity

 

[peebee]

Thanks @Agentgonzo. You've bravely stuck your head above the parapet, but now I've got you down as assistance in this pickle I've found myself. in

I reckon I've sorted @RikkiBobbi's (OP author) problem, but I seem to have unearthed my own problem that I wasn't even aware of previously. I stuck to my principal of keeping it easy (let people willing to create software calculators do the hard work for you). But the figures I'm using (post #3) have "Total Hardness" down as 54.54 (ppm as CaCO3). But 54.54 should exclude "Temporary Hardness" (in this situation effectively "alkalinity"/"bicarbonate hardness" at 13.5 ppm as CaCO3 ... therefore "Permanent Hardness" should be 54.54-13.5 or 41.04 ppm as CaCO3. Except, if I do that all the numbers fall apart.

It's prattling on like this why I encourage the use of calculators! Sweep all the prattle under a virtual carpet (water calculator).

Hang -on?

This might be a bit of "it's all alkalinity these days". Once it was permanent or temporary hardness. Is my water authority (Dwr Cymru) mixing up terms? Or terms just generally been mixed up so no-one is using a single "unified" collection of terms? I believe you can talk about "total hardness", "permanent hardness" and "temporary hardness" ... or .... "Hardness" and "Alkalinity". For tap water it's all much the muchness (in the UK anyway). But it seems Dwr Cymru is mixing up terms? Dwr Cymru reports "Hardness [Total]" should (in my mind) just be "Hardness", and so effectively "permanent hardness". If I want "total hardness" I need to add "Hardness" and "Alkalinity" together (both in "as CaCO3" units) ...

... and everything starts working smoothly again? Well, not entirely! This from www.lenntech.com:

"Clarke" or "English" hardness 4.68 whereas Dwr Cymru have 3.82. And "Moderately hard water"? I'm always down as "soft water". Bit more work on it methinks.

It mentions about converting hardness between HCaCO3 and CaCo3 and CO3, ...

That's why I insist on tap water! None of that, it's all bicarbonate (HCO3, pH7.5 or there abouts).

 

[Agentgonzo]

To be honest, I've never understood the difference between alkalinity and hardness. They are both measured in CaCO3, but are different somehow.

Fortunately for me, once I have the numbers, I just plug them into a calculator and add a few salts and a bit of acid

 

[peebee]

To be honest, I've never understood the difference between alkalinity and hardness. They are both measured in CaCO3, but are different somehow.

It's not measured "in", it's measured "as" ("as if" if that makes it clearer?). They're just convenient units. They picked on "CaCO3" 'cos it has a molar mass of 100 which is convenient (if using pen & paper). But I reckon it causes more confusion than convenience. [EDIT: You can display Magnesium ions "as CaCO3", just multiple by 4.1 (41.118 is closer), so my water has 1.2x4.1 ... 4.9ppm "as CaCO3" (but it obviously contains no CaCO3!). And Calcium: 2.5x19.7 (2.497 is closer than 2.5) ... 49.3ppm "as CaCO3". 4.9+49.3 = 54.2 or "Permanent Hardness", ppm "as CaCO3" (the report has it as 54.54, but tiny rounding and conversion errors probably account for that).]

As for difference between alkalinity and hardness ... I believe it's that causing my current problems, i.e. you're not the only one! Probably stems from the terms "temporary hardness" and "permanent hardness". Alkalinity and Hardness are completely different from each other, but alkalinity is near enough the same as temporary hardness, aka (bi)carbonate hardness, but covers more such as found in other situations away from drinking water. The information from water authorities isn't immune to such nonsense either! And that all means ... confusion!


The "summary" I scratched out in post #4 is still valid, unsullied by all this confusion garbage. Writing it showed me that I had a problem with my own water reports.

 

[peebee]

I promised to update that "dodgy" post #3. Well, this doesn't fix it, but works around the "problem". I'll look into the problem another day (it's Easter so I can't bug them at the Dwr Cymru for a few days). But the "dodgy" post wasn't that dodgy after all ... presuming my fix is right (any highlighting of errors I might have made will be welcome!).

In that "dodgy" post, starting from "I do get "Hardness" in "Clarke" units ... ". Actually, I get the Calcium figure more directly from the summary page : "Hardness [Calcium] (mg/l)" is the "as CaCO3" value. It doesn't include Magnesium which I'd neglected to subtract in the erroneous post (where I converted from "Clarke" which would give me the total permanant hardness, not just the Calcium hardness). I can enter this directly in the "ion concentration conversion calculator" section; or divide by a magic number (2.497, 2.5 will do) and get Ca as ppm. I do the same for Magnesium (1.2ppm) multiple by another magic number (can't be bothered with the "suck-it-and-see" approach used last time): 1.2 x 4.118 = 4.9 ppm as CaCO3 (4.1 for this "magic number" will do).
Enter all this with the other bits an' bobs into the "water report input:

The correct value for Calcium is now in place (19.7ppm). The "Hardness and Alkalinity" section still shows "Total Hardness" as 54, which it's not. It's the "Permanent Hardness", but we can't specify in Bru'n Water so ignore this "Hardness and Alkalinity" section (what it calculates for "permanent hardness" is garbage in this circumstance!). This is the work-around for Bru'n Water. Not ideal, but it has no impact on the calculations.

This is part of the "ion concentration conversion calculator" which has been handy. But the English and German Hardness output in "Calcium (ppm)"? More garbage I'm afraid, they are total (Ca and Mg) or "permanent hardness".

The English and German Hardness figures have come out marginally lower than published by Dwr Cymru, but doesn't matter because I'm not relying on them, and the difference will be swallowed up by manual brewer's additions made to match an "ideal" water profile. They've just been filled in for fun (remember, the units for these values "Calcium ppm" is an error in the software). And the values that follow are only filled in for fun too! Note I've used the iteration technique (suck-it-and-see) to fill these latter "for fun" values, and the exact value are hidden because of the software restricting (quite rightly!) the number of decimal places. Only the first two (three?) entries were useful in this section (Calcium and Magnesium) and perhaps the "Nitrate" because it was reported in those weird units that needed converting to ppm. Nitrate was a significant quantity in the water and so was useful to include only to balance ions as a sanity check for the figures (nitrate, iron and potassium often come in useful for this purpose, otherwise have no real value to the "beer-brewing" angle).

Do remember, this was an example employing Bru'n Water. If you use a different calculator I'm hoping some of the tips and tricks will be useful in translating to that other calculator.

Also remember I've kludged entries in this calculator to work around an issue with the way things have been reported in this case. This makes the calculated "Permanent Hardness, as CaCO3 (ppm)" value invalid.

 

[peebee]

The "Hardness and Alkalinity" section still shows "Total Hardness" as 54, which it's not. It's the "Permanent Hardness"

More garbage I'm afraid, they are total (Ca and Mg) or "permanent hardness"

This makes the calculated "Permanent Hardness, as CaCO3 (ppm)" value invalid.

Sorry! ... Getting me knickers twisted up. Or at least me "permanent" and "total" hardness twisted up!

I am known for trying to sleep on the ceiling too.

 

[peebee]

To be honest, I've never understood the difference between alkalinity and hardness. They are both measured in CaCO3, but are different somehow. ...

You think you were having trouble understanding hardness. I was making a complete dogs' dinner of it!

Sorted now? Normality resumed. Except, I'm really not that "normal"!

 

[peebee]

I have been struggling with that "Basic" Dwr Cymru water report. It had two big holes in it that I was trying to work around for this thread: "Hardness [Magnesium] (mg/L)" and "Calcium (mg/L)" which was the one missing from the report in the OP too.

I'd figured out "Hardness [Magnesium] (mg/L)" is the "as CaCO3" value; and all it needed was the "Magnesium (mg/L)" figure multiplied by 4.1 to be complete, and likewise the blank "Calcium (mg/L)" box only needed the "Hardness [Calcium] (mg/L)" figure divided by 2.5. Fortunate really, because if I had realised it, I wouldn't have had a good example with which to answer the question in the OP.

But, it was a good example of "as CaCO3" being used for real ... as a "common denominator". There wasn't even any "CaCO3" in the Magnesium example just to rub it in better. Pity about the confusing "as CaCO3" tag though. I propose ... we drop "as CaCO3" and replace it with "As Cacoe" . Now, if it was "Hardness [Calcium] (mg/L)"it will be "Hardness [Calcium] (as cacoe)". What an improvement! And to think they tried to put me in a Loony Bin!

 

[Dazzelknight]

Iv been reading this thread with great interest,, wanting to “Burton” my water as it’s a little on the hard side ! alas I’m a thicko and still can’t get my head around it … I’l leave this link here maybe some kind sole will do it for me 23L batch !
Water Quality Report 2022

 

[peebee]

Iv been reading this thread with great interest,, wanting to “Burton” my water as it’s a little on the hard side ! alas I’m a thicko and still can’t get my head around it … I’l leave this link here maybe some kind sole will do it for me 23L batch !
Water Quality Report 2022

Baffling! I thought I'd see if I could give a hand (us thickos must stick together). But looking through the Jersey Water publications ...

First things I look for are Calcium, Magnesium, Carbonate/Bicarbonate, Hardness and Alkalinity (if it's there). What I found is ... zilch! Not a bean. They'll have it, and it's not unusual for these subjects to be published separately from all the other analyses (all the uninteresting stuff like pesticides, uranium, cyanide, etc.) I can find that stuff, which is where you find sodium, sulphate and chloride. But calcium, etc.?

You'll have to contact them.

 

[Dazzelknight]

Baffling! I thought I'd see if I could give a hand (us thickos must stick together). But looking through the Jersey Water publications ...

First things I look for are Calcium, Magnesium, Carbonate/Bicarbonate, Hardness and Alkalinity (if it's there). What I found is ... zilch! Not a bean. They'll have it, and it's not unusual for these subjects to be published separately from all the other analyses (all the uninteresting stuff like pesticides, uranium, cyanide, etc.) I can find that stuff, which is where you find sodium, sulphate and chloride. But calcium, etc.?

You'll have to contact them.

Thanks for looking !.. yep I couldn’t make head nor tail of it… Uranium levels are low so I guess I can’t brew any Chernobly !!

 

[peebee]

Cor! Saw this in that "similar threads" business at the bottom of the threads you're browsing. Crikey, this was only earlier this year! It was all the tortuous grubbing about with these incomprehensible water reports that kicked me off into developing that "Defuddler" (linked in me signature below). Don't think it can untangle those worse than naff reports put out for the Channel Islands, but I'm surprised at what it can dig out. I'll bring it to bear on this conundrum sometime? ... Perhaps?

 

[Birdsnestbrewery]

Cor! Saw this in that "similar threads" business at the bottom of the threads you're browsing. Crikey, this was only earlier this year! It was all the tortuous grubbing about with these incomprehensible water reports that kicked me off into developing that "Defuddler" (linked in me signature below). Don't think it can untangle those worse than naff reports put out for the Channel Islands, but I'm surprised at what it can dig out. I'll bring it to bear on this conundrum sometime? ... Perhaps?

Not sure if it's just me but I don't see any signature or link?

 

[peebee]

That's not on! You should see this:

Report it. Or else someone will post the reason?

Meanwhile:
https://drive.google.com/drive/folders/1oxOsH7iupwt2b1ApD44ZZxPx419P-YqQ?usp=sharing

 

[MashBag]

To be honest, I've never understood the difference between alkalinity and hardness. They are both measured in CaCO3, but are different somehow.

You are not alone.

 

[Chippy_Tea]

That's not on! You should see this:

View attachment 88997
Report it. Or else someone will post the reason?

Meanwhile:
https://drive.google.com/drive/folders/1oxOsH7iupwt2b1ApD44ZZxPx419P-YqQ?usp=sharing

Thread open please reply in the new one so this can get back on track, thanks - https://www.thehomebrewforum.co.uk/threads/missing-signatures.103027/post-1234992