The Planted Tank Forum - View Single Post - Need help with Hagen Kh/Gh test
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 10-18-2006, 05:00 AM #2 Left C Planted Tank Guru     PTrader: (19/100%) Join Date: Nov 2003 Location: Burlington, NC Posts: 5,009 Your answer is on the back of the last page in the directions. Well here goes: The yellow color is your end color for the KH test. You multiply the number of drops used to get the yellow color by 10. It was 10 drops in your case. This gives you 100 mg/L or 100 ppm. If you want to convert ppm to degrees, you multiply your ppm value by 0.056 to get degrees. So 100 x 0.056 = 5.6 degrees. The GH test has a little different formula. As an example, let's say that you used 10 drops to reach the end color of light blue. For the GH test, you multiply the number of drops used to reach the end color by 20 instead of 10 like the KH test. In this example, this gives you 200 mg/L or 200 ppm. To convert to degrees, you again multiply by 0.056. So, 200 x 0.056 = 11.2 degrees. You can get degrees from ppm another way. Divide your ppm by 17.86 to get degrees. Note that both KH and GH are measured in CaCO3 equivalents. I hope that this helps.