Colour change test: fill plastic cuvette with sample water, add reagent drop by drop until colour changes from blue to yellow. Number of drops = level of carbonate hardness.
When to use: for setting up a new aquarium: once a week, afterwards once a month.
You will find detailed information and troubleshooting tips about water analysis on the JBL website in Essentials/Aquarium or Pond.
Package contents: 1 KH quick test, incl. one reagent and plastic cuvette.