carbonate confusion

[martinworswick]

i thought i had my water profile sussed,i had a report from the local water board but it was a couple of years old,
i have since got a more recent independant lab analysis report from a local micro and there are a few figures that have made me wonder if i've been using the correct one

all these below are expressed as g cac03/m3

alkalinity total 82
bicarbonate 82
carbonate <1
calcium hardness 103

i have been using the figure of 82 but i'd just appreciate confirmation this is correct.

 

[ajdelange]

If your pH is less than 8.3 then all the alkalinity is attributable to bicarbonate. Thus bicarbonate "as CaCO3" and alkalinity "as CaCO3" will be the same representing, in your case, 82/50 milliequivalents per liter (the number of moles of electronic charge on the bicarbonate ions). Note that the bicarbonate "as bicarbonate" will be 61*82/50 as 61 is the equivalent weight of bicarbonate.

 

[martinworswick]

If your pH is less than 8.3 then all the alkalinity is attributable to bicarbonate. Thus bicarbonate "as CaCO3" and alkalinity "as CaCO3" will be the same representing, in your case, 82/50 milliequivalents per liter (the number of moles of electronic charge on the bicarbonate ions). Note that the bicarbonate "as bicarbonate" will be 61*82/50 as 61 is the equivalent weight of bicarbonate.

so when i'm using the ez spreadsheet to work out additions i should leave 82 in the alkalinity box?

 

[ajdelange]

Yes.