API kH test kit results question
Hi folks, so I tested the kH in my tank this morning using the API test kit. The instructions say to add 1 drop, cap the tube, invert a few times, and repeat until water turns from blue to yellow. The instruction go on to explain that 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.
I followed the directions, and on the 4th drop water turned from blue to a very pale yellow. Just for fun, I added a 5th drop. The water was then a bright yellow. Which result is correct, the 4th or 5th drop, or does it not matter that much?