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Re: Hardness

>Date: Tue, 16 Dec 1997 23:56:00 -0800 (PST)
>From: larry at creative_net (Larry Frank)
>        Carbonate Hardness is a confusing term because it does refer to
>hardness, but rather to the alkalinity (the ability of a solution to resist
>a Ph change with an addition of an acid.) from the carbonates and
>bicarbonates. Other anions  (such as hydroxide, borates, silicates, and
>phosphates) can contribute to the alkalinity. To be absolutely correct, you
>should NEVER use the term 'kh'; however, this is often refered to in
>aquarium literature. It should be noted that it is the
>bicarbonate/carbonate buffering system which provides the majority of the
>alkalinity in aquariums plant aquariums.

Great summary, Larry.  I would only like to add the following for those who 
don't read between the lines:

1. The pH/KH/CO2 table is based solely on "carbonate hardness". 

2. All KH test kits that I know of measure alkalinity, not true KH.

3. The CO2 value you get from the table will NOT be accurate if there are other 
sources of alkalinity in your water besides bicarbonate. 

4. Even CO2 test kits are not accurate in the presence of other sources of 
alkalinity (phosphates, for sure).

George "in mild, sunny Ft. Collins, Colorado. And, um, Steve, I think the skiing 
is fine here but I'm not sure because I've never done it but I've seen lots of 
TV reports on the ski slopes with people skiing so I guess it's OK. Of course, 
if you really meant "Ft. Collins" then the skiing sucks because all the snow has 
melted and the longest run is about 100 feet even when there is snow. Unless you 
meant "water skiing".  Then it's OK but you need a wet suit because the water is 
a little chilly and you have to dodge the occasional ice chunks."