Making My Water Report Myself?

[Protos]

Water Chemistry is still esoteric to me but thanking to this board I hope I'm beginning to grasp basics of building my brewing water.
No need to delve into details, I'll just tell there's no such an option as a local water report available to me. And commercial water labs here put ridiculous prices like $100 for a comprehensive test, 33 of 40 parameters of which I don't need (they just don't do simple tests). So I brew mostly with bottled water or with custom-built distilled water.

I want to try brewing with my tap water, of which I know only that it is extremely hard (very caky on appliances) and that its quality swings wildly from time to time. However every book or article on managing tap water begins with a phrase like "first get your water report, then..." And that's where my water chemistry self-education stops.

So I'm thinking of testing my water myself, however rough and approximate such a "water report" might be.
What do you think, would a combo of pH meter, TDS meter and a fishtank test kit for GH/KH-Mg-Ca be sufficient for that matter?
Does anyone test their water like that?

 

[Silver_Is_Money]

I initially tested my well water with only the aid of a GH/KH test kit, a TDS meter, and a pH meter. The results I derived proved to be accurate within about 85% after I finally got around to having Ward Labs test my well water. Being off by only 15% is way better than purely guessing.

dH x 17.848 = ppm

GH = Total Hardness (TH) = 2.5(Ca) + 4.12(Mg)

If you make the ballpark presumption that ~70% of TH is derived from Ca++, and ~30% of TH is derived from Mg++, you can get a reasonable insight into your waters likely Ca++ amd Mg++ concentrations.

Example:

GH = 12.4 = 221.3 ppm Total Hardness (as CaCO3)

0.70 x 221.3 = 154.9
154.9/2.5 = 62 ppm Ca++

0.30 x 221.3 = 66.4
66.4/4.12 = 16.1 ppm Mg++

As a check:
2.5(62) + 4.12(16.1) = 221.3 = TH = GH(17.848)

And if you want to fly with a TDS meter only for TH computation, in my 'ballpark' experience:
Budget Metered TDS ppm x 0.85 ~= TH ppm

Then only a KH test kit is needed whereby to determine Alkalinity (as CaCO3).

 

[Silver_Is_Money]

Of course the above will leave you in the dark with respect to things like sodium, chloride, sulfate, potassium, nitrogen, iron, ...

 

[Protos]

Thank you, Silver_Is_Money, that sounds encouraging, and a useful example too!

And about the rest of the Chemical Elements, I hope there could be fishtank tests for some of them as well.

 

[Knightshade]

You could get something like this too, that is what I did.

https://www.morebeer.com/products/lamotte-brewlab-basic-water-test-kit-718901-1.html

 

[Silver_Is_Money]

It may help to know that (for consistent units such as ppm or mg/L across all contents):

TDS = Ca + Mg + Na + K + Fe + Mn + Cl + SO4 + NO3 + etc... + 1/2(Bicarbonate)
Where Bicarbonate = the HCO3- ion (nominally)
And where ppm Alkalinity (as CaCO3) = 50/61 x ppm Bicarbonate

 

[Silver_Is_Money]

And that:

Electronically Metered TDS ~= 0.62 x uS
(where uS = MicroSiemens of measured water conductivity)

 

[Silver_Is_Money]

And its interesting to know that real/honest TDS can only be measured via evaporating a certain weight of water and then weighing the residue left behind. And during evaporation right close to half of nominal Bicarbonate constituents initial weight escapes to the atmosphere as CO2 and thereby avoids post evaporation weight detection.

I believe that Ward Labs simply multiplies conductivity (in uS units) by ~0.62 whereby to report TDS.

 

[RufusBrewer]

I get 10 gallons of bulk RO water at Whole Foods for 39¢ per gallon. Solves all my water problems.

Otherwise, a report from Ward Labs at $30.00 is (IMHO) a good deal.