Water Chemistry Question

[LuukGx]

Hey guys!

I have a small question on analyzing my water profile. A quick background story, I live on a Caribbean island where it's notoriously difficult to get information from the government and government owned companies like our water provider. Through another source I obtained a water profile, but it's missing some key elements. For example there's no measurement for Calcium, but there's one for total alkalinity (CaCO3) and even though I was good at Chem in school, that is way too long and too many beers ago to have stuck with me. Could someone maybe help me translating the following numbers into relevant information?

Chloride 16 mg/L
orthofosfate <.05 mg/L
color 2.2 mg/L p+co
PH 8.1 @ 23C
total alkalinity 48 mg/L (as CaCO3)
Sulfate 2.4 mg/L (SO4-)
Fluoride 0.2 mg/L
free chloride <0.1 mg/L
TDS 54 mg/L
copper <0.02 mg/L
zinc <.2 mg/L
magnesium 0.1 mg/L

Looking at my water profile calculator I'm looking for the usual suspects. Thanks!

 

[VikeMan]

I have a small question on analyzing my water profile. A quick background story, I live on a Caribbean island where it's notoriously difficult to get information from the government and government owned companies like our water provider. Through another source I obtained a water profile, but it's missing some key elements. For example there's no measurement for Calcium, but there's one for total alkalinity (CaCO3) and even though I was good at Chem in school, that is way too long and too many beers ago to have stuck with me. Could someone maybe help me translating the following numbers into relevant information?

Chloride

I think you meant to provide more information, but I can tell you that if your water report doesn't specify Calcium, there is no way to derive it (or any other particular cation) from total alkalinity.

 

[LuukGx]

I think you meant to provide more information, but I can tell you that if your water report doesn't specify Calcium, there is no way to derive it (or any other particular cation) from total alkalinity.

Yeah it got posted cause I pressed the wrong button lol

 

[VikeMan]

Yeah it got posted cause I pressed the wrong button lol

Looking at your edited list, you're missing approximately 30 mg/L made up of (most likely) some combination of Ca and Na. 30 mg/L is approximate, because the ions have different weights/charges, but Ca and Na mg/L are almost equivalent.

But, I have to add that I'd hate to guess at how to break that down between the two ions.

 

[LuukGx]

After asking my source, apparently the water treatment plant uses RO tech to treat seawater for consumption. Looking at the list compared to others I've seen posted, it seems all my values are very low. Seeing that I mostly brew pale ales and IPA's, is there a blanket advice on what to add to treat my water for brewing? So far the only water treatment I've done is lactic acid / acid malt to bring down pH in brews with no dark malts.

 

[VikeMan]

Seeing that I mostly brew pale ales and IPA's, is there a blanket advice on what to add to treat my water for brewing? So far the only water treatment I've done is lactic acid / acid malt to bring down pH in brews with no dark malts.

Without knowing the exact calcium number, no, I can't think of any blanket advice to give. Calcium will affect (lower) your mash pH. Sodium won't.

I suppose you could compare your measured mash pH with what your model predicts with various Ca levels assumed and see what comes closest, and then use that Ca value as the presumed Ca value in the future. It's not ideal, but if you have no way to get the actual Ca number, it could be workable.

 

[LuukGx]

Using that estimation, my water profile in BrewFather states an addition of Gypsum should balance out my water, would you agree with that? I would have to play around with the amounts to see what works..

 

[VikeMan]

Using that estimation, my water profile in BrewFather states an addition of Gypsum should balance out my water, would you agree with that? I would have to play around with the amounts to see what works..

Using which estimation? i.e what did you do?

 

[LuukGx]

Added Ca & Na to the profile in various balances, starting 15mg-15mg and at all the results my Ca & SO4 were low for the styles I'm brewing

 

[balrog]

Those are low numbers, which is good, and it makes sense it is RO sourced. I'd presume enough Na and try not adding any and just add some Gypsum. Frankly, I'd make a batch without anything. Next batch, add a teaspoon gypsum and see if it really made a diff for the hops in the pale ale.

 

[LuukGx]

I've done 20ish batches without adding any salts, just last batch I treated the water with some phosporic acid and that already made a great difference.

 

[VikeMan]

Added Ca & Na to the profile in various balances, starting 15mg-15mg and at all the results my Ca & SO4 were low for the styles I'm brewing

I don't think that's going to help you, really. You won't know what mash pH to expect unless you can determine the Ca level (even if it's an estimate based on the actual measured pH of some batches vs the model).

The way you're proposing, you may know that you need some more calcium to get your pH where you want it, but you won't know how much.

 

[LuukGx]

The way you're proposing, you may know that you need some more calcium to get your pH where you want it, but you won't know how much.

So, gradually increasing it per batch while measuring with my pH meter until I hit the sweet spot maybe? I mean, I'm a noob at this stuff, so I'm just bouncing ideas off of you

 

[VikeMan]

So, gradually increasing it per batch while measuring with my pH meter until I hit the sweet spot maybe? I mean, I'm a noob at this stuff, so I'm just bouncing ideas off of you

Sort of. I'm saying measure your mash pH and then tweak the "base water" calcium number in the model so that the pH prediction matches what you actually measured. (Also include any additions you did for that batch.) In other words, "back into" an estimated calcium value.

Then going forward, you can use that same calcium number as your assumed base water calcium, and use the model to add salts/acids to target the pH that you want to hit.

I'm not sure, but it sounds like you want to come up with a rule of thumb about what to add. But considering that you already know how to use the pH model, why not derive an estimate of your base calcium level and then tailor your water additions for each batch?

I'm assuming there's no way for you to send a sample of your water to a lab for analysis (like Ward Lab in the U.S.).

 

[LuukGx]

Oh, calculate backwards, that makes a lot of sense actually! I know the starting pH from the faucet as well as my filter, so that shouldn't be too difficult. Thanks!

And for samples, the only labs here are medical labs and they're too busy to handle my request (three months at least) and to have a sample sent to the US would cost me a fortune, so if there's an easier way I'll take it.

 

[VikeMan]

Oh, calculate backwards, that makes a lot of sense actually! I know the starting pH from the faucet as well as my filter, so that shouldn't be too difficult. Thanks!

The pH of your base water doesn't matter (though the alkalinity does). You'd need to use data from an actual mash...calcium and magnesium only reduce the pH when they interact with phosphates that are in the grains.

 

[LuukGx]

Okay cool, I'm doing a double brew on Monday, i'm going to look into that!

 

[Silver_Is_Money]

@LuukGx , by balancing cation and anion mEq/L's along with guessing on the sodium and filling in the remaining blank (for calcium) it looks as if your water has a roughly 20 mg/L (ppm) Ca++ (calcium ion) concentration (and not likely more than 25 mg/L). That general ballpark for calcium should be decently close, unless your water has an oddly high level of sodium.

 

[VikeMan]

@LuukGx , by balancing cation and anion mEq/L's along with guessing on the sodium and filling in the remaining blank (for calcium) it looks as if your water has a roughly 20 mg/L (ppm) Ca++ (calcium ion) concentration (and not likely more than 25 mg/L). That general ballpark for calcium should be decently close, unless your water has an oddly high level of sodium.

How are you guessing a sodium number?

 

[Silver_Is_Money]

I initially guessed 12 ppm, but a better way might be to guess via:

MW of Na = 23
MW of Cl = 35
Cl = 16 ppm

23/35 x 16 = 10.5 ppm sodium

It's clearly a stretch. But I don't think it will likely be all that far off. I didn't run it through my software, but for 10.5 ppm sodium the calcium is likely to be about 21 ppm.

 

[catalanotte]

Check out the Brewersfreind calculator linked below with your water adjusted to the Balanced Profile. For 15 gal of source water, about 7g of Gypsum and 7g of CaCl gets you a mash pH of 5.5 and RA of -10 which should be good for all but the lightest of beers. If you play with the source water Ca between 0-20 ppm, it has a negligible effect on mash pH. Should be good brewing water, with small salt additions for lighter beers.
https://www.brewersfriend.com/mash-chemistry-and-brewing-water-calculator/?id=X9SBN59
Other assumptions used were 15 gal of treated water, 10 gal batch, 22lb grain, SRM of 5, and 0% color from roast malt.