Total Hardness or Total Alkalinity

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My water report (Sunshine Coast) has two different readings for CaCO3 and I'm not sure which one I need to use. I haven't delved deeply into water chemistry yet but I'm keen to and I would like to make sense of this conundrum.


Water.jpg
 
Water Hardness can be either Temporary or Permanent. These forms of hardness are discussed below.


Temporary Hardness results when calcium or magnesium are paired with carbonate and bicarbonate in the water. Temporary Hardness can be reduced by boiling treatment and by treatment through lime softening.


Permanent Hardness results when calcium or magnesium are paired with anions such as chloride and sulfate that cannot be driven off by boiling the water. Enhanced softening processes are required to reduce permanent hardness in water. Distillation, deionization, and reverse osmosis (RO) processes are examples of enhanced softening processes.


Total Hardness is the sum of Temporary Hardness and Permanent Hardness in the water.





2.3 Alkalinity


Alkalinity is a measure of the "buffering" capacity of a solution and its ability to neutralize strong acid and resist pH change. Alkalinity is defined as the amount of strong acid required to lower the pH of a sample of the water to a specified pH (typically 4.3 to 4.5). Alkalinity is generally due to the concentration of carbonate (CO3), bicarbonate (HCO3), and hydroxyl (OH-) ions in water. Higher alkalinity water requires more acid to change the pH.

Like hardness, alkalinity tends to vary on a regional basis. The map below illustrates how alkalinity varies across the United States (Omernik & Powers, 1983). As indicated by the map, much of the U.S. has relatively high alkalinity in surface waters. Of the regions with reduced alkalinity, many are mountainous or are regions without carbonate rock near surface. Carbonate rock and soils impart alkalinity to water

Have a read of Bru'n Water knowledge it is a good start
 
Thanks Rude, I've been reading up on it a bit lately and I've also been sitting on this question for a while, trying to work out which number is the relevant one to enter into the water calcs for brewing.

They're both listed in my report as 'mg/L as CaCO3' and brewing calculators ask for 'mg/L as CaCO3', yet both are different figures.

I've clearly missed something in my reading.

Do I enter the Alkalinity Total, or the Total Hardness figure?
 
What question are you trying to answer, What is the field called?
Is it asking for Carbonate, Hardness or Alkalinity.
Mark
 
It ask for Alkalinity, and initially I was fairly sure that I should be entering the Alkalinity figure, but my water report also has the hardness reading as mg/L CaCO3 and so I started to second guess whether that was correct.
 
If it asked for Total Alkalinity, why not put in the Total Alkalinity from your water report.
Alkalinity has a direct effect on pH, hardness not so much (tho some of it may).
The ocean is about 3.5% salts, next to none of it Calcium but its Calcium equivalent would be over 1000ppm, unless the amount of salts is way over the top, its the effect of Carbonate on the pH that you are accounting for.
Mark
 
Thanks for that, it was the way they were both reported that put doubt in my mind.

It seems rather logical, but once you start to question it, logic kind of gets pushed aside.
 
Keep at it BDDog your beers are about to improve
Read read & post questions it's all good mate
Down the track you will be telling fellow brewers about Bryn water
 

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