Lamott to Bru'n Water Spreadsheet

[Krrazy]

Hi all, quick back story -- I've been brewing all grain for ten years and about six years ago made the jump to controlling my water chemistry starting with RO water as a clean slate. I recently moved from Arizona to Pennsylvania and decided to look into using my own tap water to avoid the extra trip out to procure one more brewing ingredient.

I purchase the Lamott kit and am also a paid supporter of Bru'n Water and I'm having some difficulty using the two together (probably driven by the fact that my own grasp of water chemistry is deficient). The main concern I have is that I get a cation/anion balance that is off by 0.61 meq/L, which is noted as being a suspect value. I knew my numbers were suspect even before getting to this point however because I didn't come up with a result from Lamott that gave me a value for Carbonate and that is one of the key ions tracked in the Bru'n Water Spreadsheet.

I'm hoping someone can help me connect the dots. There's a lot to read but I'm sure other brewers have been in a similar scenario and can help me learn about this aspect of brewing. I'd be excited to hear your experiences to help me understand my situation. My results from the Lamott test are below:

Ca: 48.0ppm
Mg: 9.6ppm
Na: 4.6ppm
Bicarbonate: 324.0ppm
Sulfate: 0.0 ppm
Cl: 30.0ppm

Also from Lamott but not specifically called out on the spreadsheet:

Total Alkalinity (CaCO3): 270ppm
Total Hardness (CaCO3): 260ppm
Calcium Hardness (CaCO3): 120ppm
Magnesium Hardness: 140ppm

I do not currently have the capability to do a quality pH measurement, that's next on my list.

Thanks in advance for any help!

 

[Silver_Is_Money]

There seems to be a lot that is wrong with the above listed values. I get closer to a ballpark of ~2.8 mEq/L imbalance when using the following values:

Ca: 48.0ppm
Mg: 9.6ppm
Na: 4.6ppm
Bicarbonate: 324.0ppm
Sulfate: 0.0 ppm
Cl: 30.0ppm

And that does not account for the strong likelihood that your sulfate is in reality greater than zero.

If your total hardness is indeed 260 ppm, then my initial educated guess would be that your ballpark for Ca++ = ~83.2 ppm, and your ballpark for Mg++ = ~12.6 ppm. But even that does not bring your cation and anion mEq's into a good balance.

 

[Silver_Is_Money]

For $27.50 plus shipping you can send a sample of your water to Ward Labs and get a Brewers W-5A test which will give you decent analytical values. The only quirky oddity in their report is that to get actual sulfate ppm from the reported SO4-S ppm you must multiply the reported SO4-S value by 3.

 

[Silver_Is_Money]

Unless your water is above pH 8.3 there will not be any CO3-- (Carbonate) ions present within it. Most community supplied and/or well waters (though not all, for either case) are at or below 8.3 pH.

 

[Silver_Is_Money]

If your total hardness is indeed 260 ppm, then my initial educated guess would be that your ballpark for Ca++ = ~83.2 ppm, and your ballpark for Mg++ = ~12.6 ppm. But even that does not bring your cation and anion mEq's into a good balance.

It also may be that your Ca++ = 48 ppm (just as you stated) and that your Mg ++ = 34 ppm (not as you stated).

The key here is that whatever your calcium and magnesium ion ppm values actually are, they must comply with:

Total Hardness (as CaCO3) = 2.49730*(ppm Ca++) + 4.11796*(ppm Mg++)

Wherein the constants are derived from:
---------------------------------------------
MW of CaCO3 = 100.0869 g/mol
MW of Ca = 40.078 g/mol
MW of Mg = 24.305 g/mol
100.0869/40.078 = 2.49730
100.0869/24.305 = 4.11796

So if we begin with the initial presumptions that 48 ppm calcium and 260 ppm Total Hardness are correct, we get:

260 = 2.49730*(48) + 4.11796*(ppm Mg++)

And if we solve for ppm Mg ++ we get 34 ppm

My post #2 above presumption that led to my educated guesses of ~83.3 ppm Ca++ and 12.6 ppm Mg ++ guessed that 80% of total hardness was from calcium and 20% of total hardness was from magnesium (as water fairly often exhibits roughly this "ballpark" ratio relationship between total hardness, calcium ion, and magnesium ion).

Thus my guesses:
--------------------
0.80*260 = 2.4973*(Ca++)
Ca++ = 83.3 ppm

0.20*260 = 4.11796*(Mg++)
Mg++ = 12.6 ppm

 

[Silver_Is_Money]

With the Lamott test kit, which ppm values are specifically derived from titration, and which must be mathematically inferred? This may help us to know which ppm values you've arrived at have a better chance of being accurate.

Is this well water or community supplied water? If it is the latter, a call or visit to your local or regional water authority should bring you the current analyticals.