[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: TDS readings

>Date: Thu, 28 Dec 2000 04:56:14 -0800
>From: Steve Pushak <teban at powersonic_bc.ca>

Note to relatively new APD readers: Mr. Pushak and myself are arch-enemies
and, in the past, often taunted each other on APD. Please take this post and
any follow-ups as two grumpy old men dissing each other and have fun reading

>[B-latherings  :-) deleted]

>My main point is that the word "hardness" is really a bad term because
>it is so ambiguous.

If we all agree on what a term means, it is not ambiguous. Certainly, the
common terms we use today for ionic concentrations important to plant
husbandry are syntactically poor but they've been around for a long time
*and* they are supported by commercial test kits (which is the main point).

What we call General Hardness (degress GH or dGH) was a mistranslation of a
German term that stuck. General Hardness is measure of calcium and magnesium
concentrations and is important to plant growth since plants need calcium
and magnesium.

What we call Carbonate Hardness (degrees KH or dKH) is the measure of
carbonate ions in the water and is important in the use of CO2 which, in
turn, is important to plants. KH can't be measured directly but can be
inferred from an alkalinity test if the aquarium water is known to contain
only carbonate buffers and not phosphates, etc.

Now, what is ambiguous about that?

>I just find it so silly that, in the aquarium hobby we
>continue to use this archaic and misleading terminology!

And I suppose you would *not* find it silly to impose weighty scientific
terms to describe what is in  our water? After all, this is not

I'm sure the average plant enthusiast would not find it difficult to work in
milliequivalents, since that term is what real scientists use and it is so
much easier to use when working with chemical equations. After all how hard
could it be to convert from ppm or dKH to meq and back to determine if you
have enough calcium? And just look at how many pH-CO2-KH tables there are
expressed in meq instead of the difficult to understand ppm or dKH.

>Should we use hobbyist terminology on this email list?

Since this is not a peer-reviewed scientific journal and is primarily read
by hobbyists, ummm, why not?

> Why use a five cent word where a half dozen two-bit words will do? ;-)

And which five-cent word were you thinking about specifically? Two two-cent
words (dGH and dKH) seem less expensive and more to the point.

>Any pun~dits? George?

Yes, I'm still here looking out for the little guy who can't afford
five-cent words.

>Specifically on this weighty matter, is there a better five cent word
>than "hardness"? Is specific gravity better? I don't mean to be dense
>about this... hee hee hee... ;-)

Since *you* brought it up, I expected *you* to provide suggestions for new
terminology. But I forgot that you prefer to write long, data-filled
articles and shy away from making any concrete, useful recommendations.

George Booth in Ft. Collins, CO (booth at frii dot com)
The web site for Aquatic Gardeners by Aquatic Gardeners