Water Hardness

FishForums.net Pet of the Month
🐶 POTM Poll is Open! 🦎 Click here to Vote! 🐰

Essjay

Moderator
Staff member
Global Moderator ⚒️
Joined
Nov 28, 2006
Messages
21,159
Reaction score
18,450
Location
Teesside, UK
I've started this thread to carry on from one started in Buy Sell and Swap as this is probably the better place for it. This is the thread -
http://www.fishforums.net/index.php?showtopic=277436

So what I'd like to know is which units API use in their GH test kit. My water board has a table for the hardness in all it's areas and it says mine is 7 degrees clarke, 5 degrees german and 8 degrees french. Which one does API use? This is why I use ppm, to avoid confusion.

Last time I tested my water a few months ago (bottle expired and I've not replaced it yet) it took between 7 and 8 drops - it was always hard to decide when I'd actually reached the end point. That would fit in with clarke and french, but I'm sure I read that german is the usual one.

The thing is, as someone with a degree in chemistry, albeit from the mid 70s, I don't like all these different measurements. Surely ppm is better as there's only one way to quote that!
 
As far as I know, the API test includes a conversion chart (drops into ppm). Each drop is a range of one degree, so presumably somewhere 10-20ppm. The ppm is approximate, but it's still easier to use than degrees - I totally agree with you re. referencing hardness.
 
I always used the chart to get the value in ppm. Because I don't know which scale the API kit uses, I am wary of using the value in degrees. None of the sites I've looked at say which scale they use. The values on the clarke and french scales are very similar, but german is quite a bit different, particularly for hard water.

Which of the three scales do all the websites and test kits use? Or perhaps the question I should be asking is why does my water board use all three if everyone else uses just one? They also include a description of the hardness (medium in my case) and the total calcium.
 
From API's website:

How do I test for water hardness?
A: GH and KH are easily measured with the GH & KH Test Kit. This kit measures GH and KH in German degrees (° dGH & ° dKH) and parts per million (ppm).
 
Thank you. All confusion now cleared up.

If the water board used only one scale there wouldn't have been a problem!
 

Most reactions

trending

Members online

Back
Top