Decipher water report; missing Magnesium

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New Member
Nov 30, 2011
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Thank you for the wealth of knowledge here and really excited to finally understand and be able to adjust for my water. I believe i am either missing a few elements on the report, incorrectly entering them or the report itself is flawed. I am using brun water spreadsheet which is awesome but I've reached the saturation point of knowledge and I need to see it correctly entered and I'm not able to get there. I will copy word for word from my .pdf city water report and I would love help getting the baseline information entered.

Total Alkalinity 203 mg/L
Ammonia as N .73 mg/L
Fluoride .98 mg/L
Hardness 188 mg/L has a handwritten note pointing to Hardness saying "10.99 grains per gallon"
Calcium 3.9 mg/L
Nitrate as N .3 mg/L
Sodium 1.8 mg/L
Sulfate as SO4 .310 mg/L
Total Dissolved solids 218 mg/L

The metals report is very straightforward and I can enter that, no problem.

I really need help finding my error. My total alkalinity @ 8.5 pH spits out 240 ppm estimated Bicarbonates and 3.5 ppm carbonate. When entered in the appropriate cells in Brun, I have no way to get my ions and cations to balance and it's got to be that I don't understand something. I'm awash in standard units and conversions and I'm missing something. Calcium on the report seem way low? Seems like that's the missing factor in the balance. There is NO magnesium reported and I don't know how to solve for it.

Thanks guys,



Well-Known Member
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Aug 5, 2010
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Something is wrong here. Total hardness is 188 which implies 188/50 = 3.6 mEq/L for calcium plus magnesium. But calcium is listed at 3.9 mg/L which is 3.9/20 = 0.19 mEq/L leaving 3.4 of magnesium which is 42 mg/L. Possible, I suppose, but unlikely. If the magnesium dominated the calcium this much they would certainly list it. I'd try to get this clarified before proceeding further.