Instruction: Carbonate hardness (KH)

Take a water sample of 5 ml water.
Add 1 drop of KH liquid  and shake the test tube. The water sample turns light blue; if it turns yellow, the KH value of the water is below 1 ° DH .
Then add 1 drop of KH test liquid at a time and shake the test tube until the water sample turns yellow.
The number of drops needed to change the colour from blue to yellow indicates the KH value in ° DH.
(Example: 2 drops=2 ° DH , 3 drops=3 ° DH etc.)

Instructions: Total hardness (GH)

Take a water sample of 5 ml water.
Add 5 drops of GH-1 liquid and shake the test tube. The water sample turns dark red to purple.
Add 1 droplet of GH-2 liquid and shake the test tube until the water sample turns blue.
The number of drops, , that were necessary to change the colour from  dark red / violet to blue indicates the GH value in ° DH.
(Example: 2 drops=2 ° DH , 3 drops=3 ° DH etc.)

Instruction: Nitrate ( NO3)

Take a water sample of 10 ml .
Add 5 droplets of NO3-1 test liquid and shake the test tube.
Add 5 droplets of NO3-2 test liquid and shake the test tube.
Then add 1 measuring spoon of nitrate powder. (tube with the green cap).
Shake the test tube for 20 seconds.
Wait 15 minutes and then determine the NO3- value of the water using the colour chart.