Simple and reliable monitoring of the water values in aquariums and ponds. Determines the ideal carbonate hardness in fresh and marine water 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: daily in the first week in newly set up aquariums, afterwards once a week 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. Reagent refill separately available