Quote:
Originally Posted by mabrungard
I'm not too sure what the truth is here. The water report has some sort of error(s).
|
There may in fact be no errors at all (though, of course, there most probably are). The fact that the report does not balance does not mean it is in error. It means that it does not represent the result of analysis of a single sample or of a uniformly sampled ensemble of samples. Those numbers represent averages over some period of time (I assume 1 month). If the lab took every sample and analyzed it for all ions and averaged those then the report should balance more closely that it does. But most suppliers don't do that. They measure different parameters at different times and with different frequency. This can easily lead to an imbalance of the averages. You can easily convince yourself of this with a little Monte Carlo gaming on the computer. On top of which there may be errors in their procedures.
We can't calculate bicarbonate because we don't know what the end point of the titration used in its determination was (though this isn't a big swinger i.e. I can't appreciably improve the balance by fiddling with the alkalinity defining end point pH).
Quote:
Originally Posted by mabrungard
The Ca and Mg concentrations do not produce 105 ppm hardness. The Ca would need to be more like 30 ppm for that.
|
Total hardness is often measured by titration with a chelating agent whereas metals are often measured by AAS. The usual chelating agent (EDTA) will grab most metals and thus the total hardness can be greater than the sum of the calcium and magnesium. Strontium, in particular, can occur in fairly high concentration in some waters in the US. I have no idea as to whether this is what is responsible here but offer it as a possibilty.
Quote:
Originally Posted by mabrungard
So, I'm confused by the report.
|
I'm a bit surprised at that. I've seen lots and lots of water reports and these aren't noticeably bad relative to my recollections.
Quote:
Originally Posted by mabrungard
In any case, my analysis does not suggest that any form of acid will be needed.
|
I'm reminded of an occasion on which I was briefing some conference and a young AF Lt. stood up and stated that her model showed that the performance data (taken from the actual system) I was presenting was not possible. She asked how I would explain that. The explanation was pretty simple. Hard data always trumps an analysis (provided it is carefully collected and quality checked).
If OP manages to buy MO which is more acid than any I've ever seen, flaked barley that is more acid than I've ever seen and roast barley that is more acid that I've ever seen, and I mean more acid by an fair amount, then he might need alkali but I've done this recipe enough to know that the odds are very small. His probability of hurting himself by adding acid is much, much smaller than his probability of hurting himself by adding alkali which I'd put at over 95%. But we are dealing with probabilities and the best way to rid ones self of the associated uncertainty is a pH meter.