Water Report is Missing Magnesium

[nman13]

My water report is below but magnesium isn't listed. Is there a way to figure it out given that we have calcium and total hardness listed?

Also, the first line says "Alkalinity ppm" does that mean alkalinity as HCO3 or CaCO3?

 

[cire]

Sadly, no. The measurements vary too much to predict almost anything except to say that whatever the magnesium content might be, it's probably not vastly significant. it would seem the measurements given are an accumulation of random sampling such tha any particular measurement does not necessarily coordinate with any other.

The lowest reading for calcium is 29 ppm which will produce hardness of 72.5 ppm as CaCO3, but the lowest reported hardness as CaCO3 is 63 ppm, a lesser amount, meaning a measurement taken when calcium content was lower than the lowest recorded.

You might wish to take regular TDS meter readings and consider getting a sample tested if there isn't as much variation as those figures suggest.

 

[Silver_Is_Money]

Cire is correct, the variability of your water report renders it nigh on useless, sans that it implies that at any given moment in actual time you will not know the analyticals for your water, but rather, only a broad range of potentials.

That said, the relationship between total hardness, calcium, and magnesium is:

TH (ppm, as CaCO3) = 2.5*Ca (ppm) + 4.12*Mg (ppm)

Rearranging this gives us:

Mg (ppm) = (TH (ppm, as CaCO3) - 2.5*Ca (ppm))/4.12

So if at any given moment in time you can determine both your "actual" TH and your "actual" Ca++ ppm's, you can from those values derive your Mg++ ppm (within some typically quite small error because things such as Iron are by this method being ignored).

 

[day_trippr]

That water screams for an RO system