Help reading water report

[Benfleet Brewery]

I have a water report from where I live in Essex but wanted to compare this with the one from where I work in case the profile is better suited to some beer styles I make. If so, I could collect water from there before brew days. Although I realise the report is from 2019 and the actual water I get from the tap may not be spot on with the report, I thought it would at least act as a guide. Anyway, I think I have got nearly all the information I need. Going by the averages It looks like:

Magnesium 6.3 Mgl
Sodium 44 Mgl
Sulphate 63.9 Mgl
Chloride 63 Mgl
Alkalinity (CaCO3) 187 Mgl

but can’t find out where Calcium is listed here. am I missing something?

http://twmediadevcdn.azureedge.net/waterquality/WQ Report_Z0254_Isle of Dogs South.pdf

 

[trueblue]

Where in Essex are you and where did you get the report. If it is Essex and Suffolk water it won't be very accurate going on my own experience. I had mine tested by Phoenix earlier this year and it is a lot different to yours on some of the parameters. I also test my alkalinity and calcium before each brew and the the alkalinity has changed slightly after recent rains. Last weekends brew the alkalinity was 159 and calcium 100.

 

[Benfleet Brewery]

Yes, I’m with Essex and Suffolk. The readings I gave in the OP were from the Thames water report for my work location. Will be interesting what your other measurements were. These are the ones I got for my Essex water:

Sodium 52
Calcium 107
Sulphate 110
Chloride 86
Alkalinity (CaCO3) 163

 

[terrym]

@Markk
I don't know whether the total hardness calculator mops up all the calcium and magnesium ions present and then expresses them as CaCO3 alkalinity, but if it does* and using the calculator below, and with your Mg as 6.3mg/l it requires about 64.5mg/l Ca to achieve your alkalinity of 187mg/l
I used the calculator with my Ca and Mg values and the calculated alkanity was in full agreement with the analysis value I have.
https://www.lenntech.com/ro/water-hardness.htm*Others may be able to confirm this

 

[trueblue]

My water comes from Hanningfield reservoir and my Phoenix report was

Sodium 44.4
Calcium 115
Sulphate 111
Chloride 72
Alkalinity (CaCO3)162

I should add that several years back a fellow brewer who lives about 6 miles from me and has water from the same source had a test from Phoenix at the same time as me and there were differences. We previously both had an Essex and Suffolk report which were the same generic report.

 

[strange-steve]

@Markk
I don't know whether the total hardness calculator mops up all the calcium and magnesium ions present and then expresses them as CaCO3 alkalinity, but if it does* and using the calculator below, and with your Mg as 6.3mg/l it requires about 64.5mg/l Ca to achieve your alkalinity of 187mg/l
I used the calculator with my Ca and Mg values and the calculated alkanity was in full agreement with the analysis value I have.
https://www.lenntech.com/ro/water-hardness.htm*Others may be able to confirm this

Here's a good example of the confusion caused by hardness and alkalinity both being expressed as CaCO3, when in fact they are very different values.

 

[Benfleet Brewery]

@Markk
I don't know whether the total hardness calculator mops up all the calcium and magnesium ions present and then expresses them as CaCO3 alkalinity, but if it does* and using the calculator below, and with your Mg as 6.3mg/l it requires about 64.5mg/l Ca to achieve your alkalinity of 187mg/l
I used the calculator with my Ca and Mg values and the calculated alkanity was in full agreement with the analysis value I have.
https://www.lenntech.com/ro/water-hardness.htm*Others may be able to confirm this

Thanks @terrym. Well, that would certainly make sense. I’m not trying to get bang on, especially using the generic water report, but getting in the ball park will do me.
unless anyone comes along to say you were talking gobbledegook I’ll go with that

 

[terrym]

Here's a good example of the confusion caused by hardness and alkalinity both being expressed as CaCO3, when in fact they are very different values.

Its good to know that.
But as I said in my post against what I wrote 'Others may be able to confirm that' and so if what I am saying is a load of old whatsits, perhaps you could put me, and perhaps others, on the straight and narrow, in words of one syllable. The last thing I want to do is to chuck out confusing information, rather it be helpful.

 

[strange-steve]

Its good to know that.
But as I said in my post against what I wrote 'Others may be able to confirm that' and so if what I am saying is a load of old whatsits, perhaps you could put me, and perhaps others, on the straight and narrow, in words of one syllable. The last thing I want to do is to chuck out confusing information, rather it be helpful.

As I understand it, "as CaCO3" is typically used for hardness and alkalinity because the molar weight of calcium carbonate is 100g which makes calculations easy.

What it refers to with regards to hardness, is how much CaCO3 would theoretically have to be added to water to achieve the same concentration of calcium. For alkalinity it refers to the amount of CaCO3 that would give the same amount of alkalinity, although at typical tap water pH levels carbonate doesn't really exist in tap water as it's converted to bicarbonate.

So put simply, hardness as CaCO3 can be used to estimate the calcium content if you know the magnesium content, or vise versa. Alkalinity as CaCO3 can be used to calculate bicarbonate content. So even though they are using the same unit they are measuring two very different things.

Perhaps @peebee can chime in here to clarify or correct what I've said here, he probably understands this beer than I do.

 

[Benfleet Brewery]

Ah, so if I’ve got this right and the numbers are correct in the Water report (total hardness 265, Magnesium 6.3) the calculated calcium is about 55?

 

[strange-steve]

Ah, so if I’ve got this right and the numbers are correct in the Water report (total hardness 265, Magnesium 6.3) the calculated calcium is about 55?

No, your water report actually has values for both hardness and alkalinity as CaCO3:

265 ppm hardness as CaCO3
187 ppm alkalinity as CaCO3

Using that hardness and the magnesium value you can estimate calcium to be about 96 ppm. The problem here is that, as @trueblue says, there's a big swing between the min and max values on that report.

 

[PhilBrew]

Hi Steve

As I understand it, "as CaCO3" is typically used for hardness and alkalinity because the molar weight of calcium carbonate is 100g which makes calculations easy.

... I would have thought that some of the reasoning to use that measure would also be about the fact that limestone (CaCO3) is one of the most abundant of the soluble minerals that are likely to be dissolved in drinking water (here in Europe/North America, anyway) so it is likely that a fair proportion (maybe majority, more often than not) of the hardness is likely to be made up of CaCO3

Hi Terry

I wrote 'Others may be able to confirm that' and so if what I am saying is a load of old whatsits, perhaps you could put me, and perhaps others, on the straight and narrow, in words of one syllable.

... I don't know about "words of one syllable", this is a complicated area after all, and the explanations of the differences between hardness and alkalinity will often end up talking about "multivalent metal ions" compared with "ability to neutralise acids" ... so let me instead give you some examples of how the calculations you made could easily be invalidated, to illustrate the differences between hardness and alkalinity instead of explain them ... were some water to flow across beds of gypsum (CaSo4) then that would increase its hardness (there's extra calcium in there) but not increase it's alkalinity (no extra carbonates or bicarbonates), so the CaCO3 (hardness) measure would be increased but not the CaCO3 (alkalinity one) ... alternatively, had the water been in contact with the mineral nahcolite (NaHCO3) then that would have increased alkalinity (expressed as CaCO3) but not added to the hardness measure (also expressed as CaCO3) ... if your water has hardness and alkalinity figures that happen to match each other then you just need to recognise that that's an interesting point about your water, but we should never assume that the two can be compared (generally) and used as if they should be the same :hat:

Cheers, PhilB

 

[terrym]

As I understand it, "as CaCO3" is typically used for hardness and alkalinity because the molar weight of calcium carbonate is 100g which makes calculations easy.

What it refers to with regards to hardness, is how much CaCO3 would theoretically have to be added to water to achieve the same concentration of calcium. For alkalinity it refers to the amount of CaCO3 that would give the same amount of alkalinity, although at typical tap water pH levels carbonate doesn't really exist in tap water as it's converted to bicarbonate.

So put simply, hardness as CaCO3 can be used to estimate the calcium content if you know the magnesium content, or vise versa. Alkalinity as CaCO3 can be used to calculate bicarbonate content. So even though they are using the same unit they are measuring two very different things.

Perhaps @peebee can chime in here to clarify or correct what I've said here, he probably understands this beer than I do.

Thankyou.
That makes sense.
Given what you said I looked again at my water values and the calculator I linked and it was total hardness I was using not alkalinity which explained why I was getting agreement with the numbers.
And the same calculator also confirms Ca 96/ Mg 6.3/ TH as CaCO3 265/266 all as mg/l.
Would it be correct to assume that if a member has a water analysis that excludes Mg but has Ca and Total Hardness values, they can establish Mg by using the linked calculator as I did for Ca.

 

[Benfleet Brewery]

Ok, I’m there now, thank you.

so @terrym had the calculation correct but used CaCO3 Alkalinity instead of CaCO3 total hardness as a base whereas I just totally misread total hardness as 165 instead of 265!

 

[terrym]

Hi Terry ... I don't know about "words of one syllable", this is a complicated area after all, and the explanations of the differences between hardness and alkalinity will often end up talking about "multivalent metal ions" compared with "ability to neutralise acids" ... so let me instead give you some examples of how the calculations you made could easily be invalidated, to illustrate the differences between hardness and alkalinity instead of explain them ... were some water to flow across beds of gypsum (CaSo4) then that would increase its hardness (there's extra calcium in there) but not increase it's alkalinity (no extra carbonates or bicarbonates), so the CaCO3 (hardness) measure would be increased but not the CaCO3 (alkalinity one) ... alternatively, had the water been in contact with the mineral nahcolite (NaHCO3) then that would have increased alkalinity (expressed as CaCO3) but not added to the hardness measure (also expressed as CaCO3) ... if your water has hardness and alkalinity figures that happen to match each other then you just need to recognise that that's an interesting point about your water, but we should never assume that the two can be compared (generally) and used as if they should be the same :hat:

Cheers, PhilB

Thanks for that explanation
So the calculator I linked is nowt to do with alkalinity, it is, as it says, only 'total hardness' it uses. So does this include all calcium whether as sulphate permanent hardness or bicarbonate temporary hardness (or both?), which was my original assumption, and why using my water analysis as an example (with total hardness not alkalinity ) it gave good agreement.

 

[PhilBrew]

So does this include all calcium whether as sulphate permanent hardness or bicarbonate temporary hardness (or both?)

... yes, all calcium, however it's ended up in your water ... more accurately, that calculator includes all calcium and all magnesium, but you're then comparing it with a hardness figure (from your water report) which will have measured all the calcium and all the magnesium (and all the beryllium, strontium, barium ... basically all the "alkaline earth metals" in column 2 of the periodic table (link) ... but there'll be diddley-squat of those others, realistically)

Cheers, PhilB

 

[strange-steve]

I would have thought that some of the reasoning to use that measure would also be about the fact that limestone (CaCO3) is one of the most abundant of the soluble minerals that are likely to be dissolved in drinking water (here in Europe/North America, anyway) so it is likely that a fair proportion (maybe majority, more often than not) of the hardness is likely to be made up of CaCO3

I really don't know why it's used, but yes that makes sense.

Would it be correct to assume that if a member has a water analysis that excludes Mg but has Ca and Total Hardness values, they can establish Mg by using the linked calculator as I did for Ca.

Yes