# Noob needs help with API KH/GH test.



## Blah4Life (Jan 13, 2012)

Hello!

Do I add the total number of drops from the KH test to the number needed in the GH test and THEN consult the conversion chart with the grand total of drops used?

I'm really confused with how I come up with the value for each using the chart. Maybe I'm either stupid or totally over thinking it...


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## nvladik (Jan 12, 2012)

I believe the two tests are totally separate. Just count the number of drops until the color changes. But that's from memory, haven't done it in a while.


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## Blah4Life (Jan 13, 2012)

That would make sense. I guess I'm just a little confused by the conversion chart they provide, I guess.


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## pandamonium (May 14, 2012)

from what i understand you count the total number of drops from the first one you put in until the color change happens. when i did that i got reasonable numbers that were consistent with the numbers put out in my water quality report. i guess its some kinda of titration?


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## lipadj46 (Apr 6, 2011)

You count the number of drops and that is your GH or KH in degrees hardness. If you want ppm multiply the degrees hardness by 17.


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## Alastair-T (Jun 5, 2011)

With the gh, it's however many drops it takes after each shake to turn your sample from yellow to green, so say 6 drops gives you a gh of 6. Same with the kh. The solution needs to go yellow 


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## Diana (Jan 14, 2010)

Ditto: Just count the drops. 

I find the color change hard to see in the GH test. Make sure you are looking at it in good light, but without anything green nearby to reflect into the test tube. 
The KH test (Blue/Yellow) is very obvious. 

If you want to fine tune it you can double your sample size (use 10 ml of water) then you can figure it down to about .5 degrees. I am not sure the test is accurate beyond that though. I do that if the color change happens at just one drop. I do not bother if the color change happens at any higher level. In fact I do the opposite. Use half dose of water (2.5 ml) and call each drop 2 degrees.


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## Monster Fish (Mar 15, 2011)

If your water is very soft, it might take only one or two drops for the color of the solution to change. In Queens, I've measured the tap to have a GH of about 1-2 and the KH at the same value. I've used Diana's method of using a 10 ml sample size, but instead of using the test tubes, I used a white paper cup since it's easier to see the color change. The change in color for the solutions is also very faint, at least in my experience. For example, with the GH it took only two drops of the solution to change the water from orange to light green using a 10 ml sample.


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## Diana (Jan 14, 2010)

I will try the white cup idea. I am having a hard time seeing the change in the test tube, and most of the tanks have a GH of about 4-6 degrees. (Mostly 2-3 drops using 2.5ml of water as the sample)


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