Help With Water Profile Entries - Beersmith / Bru'n Water

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Kaiden

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Using the iDip system, my water came back as:

Results

Test Name: Sodium
Test Result: 4 ppm

Test Name: Residual Alkalinity as CaCO3
Test Result: 17 ppm

Test Name: Magnesium Hardness MG
Test Result: 21 ppm

Test Name: Sulfate
Test Result: 1 ppm

Test Name: Hardness, Total (as CaCO3)
Test Result: 21 ppm

Test Name: Chloride
Test Result: 13 ppm

Test Name: Calcium Hardness (as CaCO3)
Test Result: 0 ppm

Test Name: Alkalinity, Total AL
Test Result: 20 ppm

Question is, I can't figure out how to plug these numbers into Brun Water correctly as my test does not have Bicarbonate. Also I am not sure if my other perimeters are entered correctly as it does not say if they are CaCO3. Apologies in advance for bugging, just really would like to figure this out and so far this spreadsheet is frustrating..

I have Beersmith and do like to adjust my PH with Phosphoric Acid so would like to use Bru'n Water in addition to Beersmith....

Thanks in advance...
 
The fundamental water parameter is alkalinity, not bicarbonate. If bicarbonate is given then the pH must also be specified to the program so that it can figure out the alkalinity which is what it needs to do its calculations.

Many of the popular spreadsheets are lazy in this regard getting by with the approximation (which is actually a fairly good one in the proper pH range and the reason they get away with this) that alkalinity = 50*bicarbonate/61. This means that bicarbonate = 61*alkalinity/50 and if you have a program that demands bicarbonate you can just use 61*alkalinity/50 for its value.

As the sum of the magnesium and calcium numbers is equal (approximately) to the total hardness which is expressed 'as CaCO3' it is clear that the magnesium and calcium values are also hardnesses in the same units. Use 20*calcium/50 and 12.15*magnesium/50 for the concentrations of those ions in mg/L
 
Ajdelange.. Thank you very much for the reply.. Please bare with me as I am new to the water game... Simply have guesstimated for the past 5 or 6 years and have been fortunate to have low mineral water.

Can you explain the way you are writing this?

Example - alkalinity = 50*bicarbonate/61

My mind wants to understand, it's just not working at the moment.. Sorry to be a pain! Also am very appreciative of the replies as I am committed to learning this water process.. If only I can stop falling asleep while reading the Water Book.. SMH....
 
If I could bother to ask what numbers you would plug into Bru'n Water, this may just give me an idea of what I am looking at in regards to the conversion..
 
Alkalinity was 20 ppm as CaCO3 (because alkalinity is in the same units as Residual Alkalinity). Twenty ppm as CaCO3 means that the analyst dded 20/50 = 0.4 mEq of acid to each liter of the water in order to reduce its pH to 4.5. That is the definition of alkalinity. From alkalinity and pH we can calculate the amount of acid you as a brewer would need to add to the water to reach any mash pH you chose or, in other words, how much you would need to 'neutralize' this alkalinity. It's usually 80 - 95% of the alkalinity number so in your case if your water's pH were 9 and you wanted mash pH of 5.4 you'd need 0.371 mEq acid (92.8% of 0.4 mEq ) for each liter of the water but if your water's pH were 6 you would only need 0.346 mEq/L (86.4%). Now this is how a chemist would approach things but the guys that write spreadsheets aren't chemists (and neither am I) so they try to simplify. The math required to do it as I have described isn't difficult and is all set out at https://www.homebrewtalk.com/showthread.php?t=473408 but the spreadsheet authors reason 'all the alkalinity in potable water comes from bicarbonate' and calculate the acid required based on that. The problems with this are two: first all the alkalinity doesn't come from bicarbonate if the pH is high and it doesn't all come from bicarbonate if there is carbonate or phosphate in the water and it doesn't all come from bicarbonate if you have put lime or lye into the water to increase its alkalinity. Assuming that you didn't do any of those things and that the pH is moderate a mEq of bicarbonate in liter of water will require you to add a mEq of acid in order to bring the pH of the solution to pH 4.5. The equivalent weight of bicarbonate is 61 mEq/mg so the alkalinity of a solution of x mg/L bicarbonate is x/61 mEq/L. It is customary in North America to express alkalinity 'as CaCO3' and this is done by multiplying the mEq/L by 50 so x mg/L bicarbonate results in alkalinity of 50*x/61 ppm as CaCO3. If you have y ppm as CaCO3 alkalinity and assume that it all comes from bicarbonate you first convert the ppm as CaCO3 to mEq/L and then multiply by the equivalent weight of bicarbonate, 61 to get 61*y/50 as the mg/L bicarbonate estimate. For your alkalinity of 20 the estimated bicarbonate is thus 61*20/50 = 24.4 mg/L. That is what you should put into these spreadsheets if they demand bicarbonate but I thought most of them were sophisticated enough to accept an alkalinity input as well by means of a radio button even if all they do is convert it to bicarbonate. The second problem with the bicarbonate approach is that the bicarbonate number given on most water reports is often miscalculated.

For alkalinity of 20 the actual bicarbonate numbers

pH bicarbonate
6 23.6
7 22.8
8 22.1
8.5 20.8
9 16.7

61*20/50 = 24.4

The reasoning is similar where metals are specified 'as CaCO3'. To convert to mg/L you divide by 50 to get the hardnesses as mEq/L. In this case it is not mEq/L acid required to move to a particular pH but mE/L of a chelating agent (EDTA) required to remove the metal from the solution. The equivalences are then multiplied by the weights of 1 mEQ of the metal. For a magnesium hardness of 21 you would have 12.15*21/50 = 5.1 mg/L because the equivalent weight of magnesium is 12.15 mEq/mg. For the calcium you have 20*0/50 = 0. Those are the numbers you would put into a spreadsheet that wants mg/L ('as the metal') rather than hardnesses.
 
Thanks Aj... After about 3 times reading it I think I understand! I just don't understand why they can't just cater everything to my brain... Lol..

Once I get all the base numbers for Bru'n Water I think I can figure the rest out... It's simply the test result conversions which is stumping me...
 
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