🚀 go-pugleaf

Fernando Pineda (fernando@aplcomm.jhuapl.edu) wrote:
: 
: Keith's post on the matter was a suggestion that there were at least two kinds 
: of  hardness. An interesting suggestion, but what's the quantitative 
: implication?

There is no implication.  There is general hardness, which is
the amount of metal cations dissolved in the water (Ca++, Mg++, etc.),
and there is carbonate hardness, the amount of carbonate anions dissolved
in the water (CO3, H2(CO3)2?).  Your test kit measures general hardness,
and presents its results in terms of CaCO3.  However, not all of your
calcium ions necessarily have carbonate partners.  But, back to the
point - you've measured your concentration of Ca++, you want to convert
it to dH.  I do not know if you are supposed to divide ppm of Ca++ or
ppm of CaCO3 equivalents to get dH, but whichever you do, will give you
the GH in German degrees.  If you want your carbonate hardness, KH, which
is supposed to be in the neighborhood of 7-13 dH (not being a marine
person, I don't know what it is supposed to be, but our tapwater is 8 dH),
you will need a KH test kit.

: Also it seems to imply that 
: Moe doesn't have the whole picture either since he does not suggest that there 
: are two kinds of hardness and just gives a single conversion factor for CaCO3. 

I've never read one of Moe's books, but I'm quite confident that he
is aware of both general and carbonate hardness.
 

--
"They thought to use and shame me but I win out by nature, because a true
freak cannot be made.  A true freak must be born." - Geek Love

Greg Frazier	frazier@CS.UCLA.EDU	!{ucbvax,rutgers}!ucla-cs!frazier