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Re: hardness

On Wed, 20 Sep 2000, Dave Gomberg wrote:

> On the subject of hardness, I have uncovered and tried to define the 
> following terms:

Oh No!  I think he's about to break the code!!
>    Hardness:            Ca+Mg
>    General Hardness:    Soap killing (tested by titration with "standard" 
> soap solution)

	Hardness = General Hardness = Total Hardness.  Total Hardness
would actually be my preferred term.

>    Permanent hardness:  General hardness after boiling the water

	Just "hardness" after boiling the water (and all the other details
in George S.'s recent description of the method).

>    Temporary hardness:  General hardness - Permanent hardness
>    Carbonate content:   Total CO3-- (and relatives) content

	Not a standard term.  For most water compositions you're talking
about bicarbonate concentration.  Carbonate strictly speaking isn't
significant until we get to rather high pH levels -- 10 or so, I think.

>    Alkalinity:          Resistance to titration with an acid

	or more briefly "buffer capacity".

>    Carbonate hardness:  Minimum of Hardness and Carbonate content (per 
> Slusarczuk)

	wasn't carbonate hardness=temporary hardness in George's writeup?
>    KH:                  German for carbonate hardness?

	I guess.

>    Non-carbonate hardness:   General hardness - Carbonate hardness????

	In practice, Total hardness minus alkalinity, or 0, whichever is

> Does anyone disagree with any of these definitions????

No major differences.

Roger Miller