Expert: Steve Young - 11/5/2008

Question
Hi Steve,
  Recently my neighborhood was put on a different water well.
The old well it at the 500ft level, the new one at 1600ft.
   While we are awaiting a full lab generated water report, I am confused at some initial readings that I made using a Hanna Ph/TDS meter along with a chemical hardness test done locally.  Our water has a high PH of 8.2, TDS is very high, in the 1000 ppm range...yet the water is on the soft side with a hardness reading less than 20gr/g.  I always thought TDS was directly proportional to the harness..High TDS..High hardness  Obviously there are different types of TDS..The TDS I am reading relates to the conductivity of the water..What gives? Carbonate vs non-Carbonate?? Can you explain, for I am thoroughly confused....I did calibrate the meter with the correct solutions...

Thanks
Tom

Answer
Hi Tom,
The TDS is the total dissolved solids and is literally a measure of everything that is dissolved in the water.  A portion of the minerals that are dissolved in water are Calcium and Magnesium (the ions that make up water hardness).  Here is a really good explanation of TDS:

http://www.wqpmag.com/Water-Testing-101-TDS-article8837

Secondly, the hardness reading of 20gr/g is actually very hard water.  20gr/g is actually equal to 340ppm.  Soft water is generally considered to be water that has a hardness level less than 20ppm.  Anything over 120ppm is considered very hard water.  See explanation:

http://en.wikipedia.org/wiki/Hard_water

So, generally the higher the TDS the higher the total hardness but that is not always true.  Many times a high sodium concentration in the water will yield a high TDS but the water will have a low hardness concentration because sodium does not add hardness to the water.

I hope this answers your questions and didn't just confuse you more.  Let me know if I can help out in any other ways.
Take care,
Steve


Hi Tom,
Thanks for the ratings.  And yes, I do have a question.  I have been seriously thinking about getting my pilots license.  Can you give me a ballpark number on how much this would cost and about how long it would take.  I know there are different levels, i.e. vfr and ifr (or something like that) but if you could give me a ballpark figure I would really appreciate it.  And you can send it to:  SAYoungWS@gmail.com.  Thanks for the offer Tom!