Need Help Interpreting Ward Lab Results

[mbtech]

Hey guys and gals! I received my water report yesterday and I'm trying to interpret the results, in particular the total hardness vs. total alkalinity. Both of these show up as CaCO3, yet the numbers are wildly different. Which one of these two should I focus on? Do the results look flawed? See below:

pH 8.6
Total Dissolved Solids (TDS) Est, ppm 166
Electrical Conductivity, mmho/cm 0.28
Cations / Anions, me/L 2.8 / 3.0

ppm
Sodium, Na 61
Potassium, K < 1
Calcium, Ca 3
Magnesium, Mg < 1
Total Hardness, CaCO3 8
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S 4
Chloride, Cl 8
Carbonate, CO3 3.0
Bicarbonate, HCO3 148
Total Alkalinity, CaCO3 126
Total Phosphorus, P 0.18
Total Iron, Fe < 0.01
"<" - Not Detected / Below Detection Limit

 

[laredo7mm]

This might help:

http://braukaiser.com/wiki/index.php?title=How_to_read_a_water_report

 

[The_Bishop]

Those numbers look like that's water from a water softener.

 

[mbtech]

This might help:

http://braukaiser.com/wiki/index.php?title=How_to_read_a_water_report

This is very helpful and interesting. Thank you.

 

[mbtech]

Those numbers look like that's water from a water softener.

My water comes from a large well (one of about ten) in the area which is utilized by the water company. I've always assumed that it was softened because it feels slippery, although they claim it isn't treated with water softeners. With that being said, shouldn't a softened water supply read higher on the sodium levels than what I have?

 

[The_Bishop]

I'm not an expert by any means, but the very low calcium and magnesium, with a sodium of 61 and relatively high bicarbonate says 'water softener' to me. The media in a softener exchanges sodium for calcium and magnesium so the hardness of the water going in directly correlates with the level of sodium coming out of the softener.

 

[ajdelange]

Calcium carbonate has a molecular weight of 100. Thus 100 mg of it constitutes 1 mmol. The calcium content is 2 mEq (beause Ca++ is doubly charged). Were you to place 100 mg of CaCO3 in a beaker and bubble CO2 through it long enough that the CaCO3 all dissolved and the pH got to 8.3 the carbonate would have all converted to bicarbonate by the following reaction
Ca++ + CO3-- + CO2 + H2O ----> Ca++ + 2HCO3-
and the liter would contain 1 mmol (2 mEq) of calcium ion and 2 mmol (2 mEq) of bicarbonate ion. This reaction is the reaction that takes place when limestone is dissolved by carbonic acid in the ground or at the surface and represents the way in which bicarbonate finds its way into natural waters. If one sets out to measure the alkalinity of this water he would add acid to it until all the bicarbonate is converted to CO2:
2HCO3- + 2H+ ---> 2CO2 + 2H2O
Obviously it would take 2 mmol (2 mEq) of H+ ions to do this. Similarly, if one sets out to measure the hardness he add a chelating agent until all the Ca++ is complexed:
Ca++ + EDTA ---> CaEDTAte
and it is clear that if there were 2 mEq of Ca++ in the liter of water 2 mEq of EDTA will be required to suck it all up. Thus 100 mg of CaCO3 dissolved in a liter of water requires 2 mEq of acid to do the alkalinity measurement and 2 mEq of chelating agent for the hardness measurement. Some bright guy said "Hey, multiply the alkalinity acid measurement by 50 and do the same for the chelating agent and we get the number of mg/L of chalk that was responsible for that alkalinity and hardness! Provided that all the hardness and alkalinity in the sample came from limestone dissolved by CO2." Thus was born the practice of specifying calcium content "as CaCO3" and doing the same for alkalinity. Even if there is no calcium or bicarbonate in the solution! Thus, for example, a solution of 1 mmol/L Mg(OH2) has a magnesium content of 100 mg/L as CaCO3 and an alkalinity of 100 mg/L as CaCO3. Confused enough yet?

If we go back to the measurement of alkalinity it makes much more sense to stop before multiplying by 50 and just say "Alkalinity is 2 mEq/L" and in many places in the world they do just that. Similarly with the hardness measurement just say that the hardness in 2 mEq/L. With even a simple test it is possible to separately chelate the calcium and magnesium (the major sources of hardness) and one that is done it is a simple matter to multiply the mEq by the equivalent weight of the metal. Thus 2 mEq/L calcium hardness equates to 2*20 mg/L calcium ion and 2 mEq/L magnesium hardness to 2*12.15 mg/L magnesium ion. In the Ward Labs reports the calcium and magnesium entries are in mg/L of the actual ions (because they are measured by ICP and not chelation) but the total hardness number is in ppm as CaCO3 because it is measured by chelation. And the alkalinity, which is done by titration with acid, number is mEq/L*50 and thus in the archaic ppm as CaCO3 notation.

When looking at these numbers divide by 50 (very easy: multiply by 2 and shift the decimal to places to the left). Thus you have 8/50 = .16 mEq/L hardness and 126/50 = 2.52 mEq/L alkalinity. That imbalance says "Look for sodium and potassium" and, indeed, you have 2.65 mEq/L Na+.

 

[mbtech]

Thanks for the patronizing explanation. Maybe someday I can be awesome too... lol.

 

[ajdelange]

Doubtful, but there are people here who are interested in learning about Brewing Science. That's why this forum is so named.

 

[brewprint]

Not to hijack this thread, but I also just got my Ward results.

I put the results in Beersmith 2 and of course many of my values are off.

Where is a good place to start to make adjustments for mineral/chemical additions?

 

[Iseneye]

Thanks for the patronizing explanation. Maybe someday I can be awesome too... lol.

This is the brew science forum. A scientist gave you a detailed answer - he wasn't being patronizing.

 

[JONNYROTTEN]

Come on now..,This is a homebrew forum not a 4th year masters science lab. ajdelange is the forum water guru for sure but not everyone has the smarts to figure out what hes talking about even if they tried, Myself included. Sometimes a simple answer with an explanation normal folks could understand would go further.

 

[ajdelange]

I think we all know that STEM education in this country has slipped but I had no idea it was as far as all that. The important thing here is that there are plenty of people who do understand at this level (high school or perhaps college freshman level - at least when I went to school many years ago) and perhaps this forum is for them rather than you. If there is something you don't understand and want to understand then ask for further explanation.

 

[Iseneye]

Come on now..,This is a homebrew forum not a 4th year masters science lab. ajdelange is the forum water guru for sure but not everyone has the smarts to figure out what hes talking about even if they tried, Myself included. Sometimes a simple answer with an explanation normal folks could understand would go further.

Sodium levels are higher than ideal but not awful. Carbonate levels are highish and will likely require more acid to neutralize it. I would prefer to not brew with this water if RO was available.

I'm not a chemist either but enjoy reading aj's posts. I don't like the idea of him having to dumb down his responses in the Brew Science forum. I can understand the angst if the reply was in the general beer forum.

 

[JONNYROTTEN]

I will respectively withdraw my statement. I didn't notice the category. I clicked on from the "new thread" area and not from the main directory