API Carbonate Hardness Test Kit
Directions for Testing KH
Rinse a clean test tube with water to be tested.
Fill the test tube with 5 ml of water to be tested (to the line on the tube).
Holding the bottle vertically, add KH Test Solution, one drop at a time.
Be sure to count the number of drops being added.
Cap the test tube and invert several times after each drop.
The test is completed when the water in the test tube, after having been shaken, turns from blue to yellow.
If you have difficulty discerning the color after the first drop of test solution is added, remove the cap from the test tube and, while holding it over a white background, look down through the tube.
The KH value is determined by the number of drops of test solution that must be added to turn the water in the test tube bright yellow.
See GH & KH Conversion Chart at end of instruction leaflet.