Estimating Carbonate and mixing water

[lancsSteve]

I've brought back in a polypin some VERY HARD water from Norfolk to mix with my VERY SOFT Lancaster water - and hopefully make up 'perfect liquor'.

However - I have no carbonate figure from the Norfolk water - how can it be estimated based ont he figures I do have which are(all mg/l):

LancasterCaCO3 25 Calcium (Ca) 5.7 Magnesium (Mg) 0.8 Sodium (Na) 8 Carbonate (CO3)4.6 Sulphate (SO4) 9.4 Chloride (Cl) 12.3 Nitrate (NO3) 1.9
Norfolk CaCO3 363 Calcium (Ca) 120 Magnesium (Mg) 4 Sodium (Na) 12 Carbonate (CO3) ?? Sulphate (SO4) 63 Chloride (Cl) 45 Nitrate (NO3) 24


These figures are taken from the respective water companies and then balanced within their published ranges using the ION balancing calculator here: http://users.tinyonline.co.uk/chrisshort/ib.htm

Can anyone help me calculate the carbonate for the Norfolk water?

And if I want to mix the water to make 'good liquor' - one for bitter one for lager are the ratios going to be simple (i.e. just calculate each according to appropriate proportion in liquor until target liquor is reached) or does something much more complex happen if mixing two different water sources? I'll be treating the mash water as priority (15l +/-) and possibly the sparge water too if possible/appropriate.

Of course if anyone felt like working out the appropriate proportions I'd welcome that too

[Aleman]

Buy a salifert Total Alkalinity test kit and test it yourself . . . then mix the water in proportion to end up with the alkalinity you want . . . and then test it and adjust as required using CRS.

FWIW I mix my water with my my in laws (Lowestoft) water in a ratio of 2 to 1 and end up with a total alkalinity of around 110 then adjust back to 75ppm using CRS . . . . Of course I could always use 3to 1 and not do the acid adjustment.

[lancsSteve]

Norfolk Hardness as CaCO3 363

Are you absolutely sure about the level of carbonate in Norfolk water, you haven't got the Total Hardness as CaCO3 figure there have you ?

The figure ( 363 CaCO3) is from:

Water Hardness
To aid the setting of domestic appliances, the water hardness is 363 mg/l as calcium carbonate.

But no figure for 'carbonate' to put in the calculator - hence trying to find out how to estimate it from the figures I do have.

Getting the CaCO3 figures added is pretty easy - but it's trying to get the missing figure to go into the calculator that I'm after. I have them all in a spreadsheet with different ratios calculated so I can put those into the water calculator and see which will work best for different beers.

Eventually I'll get some test stuff but for now I'm keen to try working the numbers through beer calculator - but that's only gonna work if I can estimate the carbonate from the other figures...

The site does allow you to convert/express hardness as other figures:

Conversions of calcium carbonate 363 mg/l to:
calcium (milligrammes per litre) = 145.2 | degrees Clark = 25.265 | degrees French (°f)36.3 | degrees German (°dH) = 20.618 | millimoles of calcium (mmol/l) = 3.63

But again, no bicarbonate or carbonate figure

From a previous thread on Mash pH:

Of course, there is a considerable amount of confusion over the terminology "alkalinity" because of the various ways of expressing it. Three or four different numbers to express exactly the same thing. Carbonate is what alkalinity really is, but British water companies (and Brupaks) have the habit of expressing it as calcium carbonate, which is nonsense and misleading. If alkalinity was always expressed as carbonate or even bicarbonate, rather than calcium carbonate, the confusion between alkalinity and hardness would be greatly reduced.

To express 50mg/l of carbonate (which is 1.67 millequivalents as above): 1.67 * 50 = 83.5mg/l CaCO3
Where 50 is the equivalent weight of calcium carbonate.

So.... can I reverse that to calculate that 363 CaCO3 / 1.67 = 217 Carbonate???
Which also equals 363mg/l CaCO3 - 145.2 mg/l calcium = 217 mg/l Carbonate???

Or have I totally misunderstood this relationship

I did find this: http://comp.uark.edu/~ksteele/hc2004/AL ... LATION.htm but got lost trying to figure out where the figure for K came from

[WallyBrew]

From the figures you have given the calcium carbonate is 194mg/L. I would think this is lower than it really should be.
Most waters also contain potassium but water undertakers no longer appear to test for it and neither do Murphys who also do not do sodium.
You wil probably have about 4 to 6 mg/L of potassium and in many waters all of the chloride relates to the sodium and potassium.
If this is the case then the alkalinity will be 231mg/L as calcium carbonate. And assuming 4mg/L of potassium the new sodium figure will be 27.

You can test this by entering all the original figures you gave into the Chris Shorts calculator and 236 in the alkalinity (this is as HCO3).

If you enter 194 it will tell you you have an unbalanced water (or it did last night) so you have to enter 388 instead. There is/was something wrong with the calculation. [edit Chris Short has corrected this as of today]

Buy a test kit.

And K is potassium

[lancsSteve]

From the figures you have given the calcium carbonate is 194mg/L.

Where does that come from / how is that calculated? Is that on a 50/50 mix or is 363 mg/l CaCO3 as per the water report for norfolk just plain wrong?

If you enter 194 it will tell you you have an unbalanced water (or it did last night) so you have to enter 388 instead. There is/was something wrong with the calculation.

I wonder if this was working with incomplete data? I've used the figures for bothLancaster and for Norfolk and then for mixes of the two and always come out balanced.

I didn't give the potassium figure above but it was in water report as 2.27 for Norfolk (and seems to be 0 for Lancaster)

Equally they all balance fine at 50/50 etc. from my spreadsheet figures.

Hopefully my carbonate calculation above is correct (two ways of reaching the same number seems promising ) so will experiment with ratios and entering calculated figures the water treatment calculator to see what combo will make a good mix. 50/50 would be my maximum but as I'm next brewing a dark lager hopefully don't need to add a lot of hardness/alkalinity.

Buy a test kit.

And K is potassium

Thanks - I think will they're cheaper than I feared but I don't expect to be any less confused after testing - or will I get individual reliable figures for each entry into the water calculator using one?

[WallyBrew]

From the figures you have given the calcium carbonate is 194mg/L.

Where does that come from / how is that calculated?

This will probably make it as clear as mud but here goes

You sum up the milliequivalents (meq) of the cations and subtract from it the sum of the meq of the anions.

To get meq you multiply the quantity present by the charge on the ion (ignoring the sign + -) and divide it by the molecular/atomic mass.

So, and ignoring all those pointless decimal places people like using because it makes little difference to the outcome, we get:

for the cations
Sodium 12 x 1 / 23 = 0.52
Magnesium 4 x 2 / 24 = 0.33
Calcium 120 x 2 / 40 = 5.99
Potassium 0 x 1 / 39 = 0

for the anions
Chloride 45 x 1 / 35.5 = 1.27
Nitrate 24 x 1 / 62 = 0.39
Sulphate 63 x 2 / 96 = 1.31

So:

cations - anions = 6.84 - 2.97 = 3.87

The water is unbalance by 3.87 meq and it is assumed that this is due to bicarbonate. To convert this to calcium carbonate where the charge is 2 on both ions of the molecule multiply it by the molar mass of calcium carbonate (100) and divide by the charge (2)

3.87 x 100 / 2 = 193.5


The 363 figure you have is hardness expressed as calcium carbonate AND HAS ABSOLUTELY NOTHING TO DO WITH ALKALINITY SO IGNORE IT.

However the figure given cannot be calculated from the figures provided so here is the calculated version:

To get the total hardness convert magnesium to its equivalent as calcium
4 / 24 x 40 = 6.66

Add this to the calcium 120 + 6.66 = 126.66 and multiply by 2.5 to convert it to calcium carbonate = 317

I think that the figures you have extracted from Norfolk seem to be a bit dubious and trying to calculate anything more will probably lead to even more confusion.

[lancsSteve]

Wow those are some hectic calculations - working my way through them would the answer be that I should add 'a bit' of hard water for a lager and 'more' for a bitter?

I think that hits my level of desire to get into this level of equations! And I thought it might be easier to mix hard and soft water rather than try adding Gypsum and epsom salts

I know my water is super super super soft and Norfolk water is really hard (giving the lie to the old north/south split - or are people inversely correlated to water hardness?) and I do have a good electronic pH pen to test mash pH so think I'll treat this as an experiment, but maybe less scientific than originally planned!

Cheers for all the help!