Reef Chemistry Question of the Day #41 dKH word origin

[Randy Holmes-Farley]

[h=3]Reef Chemistry Question of the Day #41[/h]
As a break from our normal questions, we’ll have a word origin problem today!
There are a variety of different units for total alkalinity used by reef aquarists. One that is commonly used is dKH, which is just pronounced (by normal Americans, at least) like the three letters D K H.


Which of the following is closest to the origin of this use of the term dKH?


A. It is Latin: “dacite Kalator Halatioâ€
B. It is Latin: “decimus Kalx Hactenusâ€
C. It is English: “ ° Karstic Hardnessâ€
D. It is English: “ ° Kathodic â€
E. It is German: " ° Karbonathärte"
F. It is German: “ ° Kärbon Halkaliâ€


Note ° is the degree symbol


No fair looking it up!


Good luck!


































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[reef lover]

E it is german

 

[beaslbob]

How should I know.

I hardly speak english

 

[ASAP-Aquarium]

The answer is E.

 

[Zero Nitrates]

How about C

 

[ritter6788]

My guess is E as well.

 

[leptang]

E thats easy to find out on the internet.

 

[Steven@]

E is my answer as well

 

[jt17]

don't knowicus the answerus

 

[dmann]

I'm going with B

 

[DFW]

E!!

 

[Randy Holmes-Farley]

Anyone else want to take a stab before I post the answer?

 

[dmann]

Would like to know. Lol

 

[Randy Holmes-Farley]

And the answer is... E. It is German: " ° Karbonathärte"

It basically translates as degrees carbonate hardness.

Here's a longer description:

dKH

dKH stands for the German term “degrees of carbonate hardness.” It is a unit of alkalinity, and is equivalent to 0.36 meq/L or 17.8 ppm calcium carbonate equivalents. There are other related units that have similar names, such as Clark degrees, but they are rarely used by reef aquarists. Hardness is most often used to refer to calcium and magnesium in solution, but “carbonate hardness” evolved from the assumption that in fresh water, much of the carbonate comes from weathering of calcium and magnesium carbonates. So some units of measure (like dKH and ppm calcium carbonate equivalents) refer to the concentration with respect to the amount of calcium carbonate that would need to dissolve into the water to produce that alkalinity.

It is from:

The Units of Measure of Reefkeeping by Randy Holmes-Farley - Reefkeeping.com