BWT Hot Beverage Total Water Hardness and Carbonate Test Kit (KH+GH) measure the total hardness of your water and the carbonate in your water.
The kit includes 2 vessels for water and 2 color tester solutions.
The blue tester is for measuring total water hardness. Fill the one vessel with water, add a droplet to the water. Count how many droplets it takes to turn the water from red to green. Each droplet counts as one degree GH of hardness.
The yellow test kit is to measure the amount of carbonate in the water. follow the same procedure as above except using the yellow bottle. The droplet count is the degree KH of total carbonate.