JBL Test PRO KH Carbonate Hardness Test

JBL Test PRO KH is a drop test for measuring the carbonate hardness of aquarium water.

It suits freshwater and marine aquariums and ponds.

The test works by colour change. The number of drops gives the carbonate hardness in degrees (°dKH). According to the manufacturer KH should never drop below 4 °dKH. The manufacturer recommends 5–12 °dKH for a community freshwater aquarium and 3–8 °dKH for a planted aquarium with few fish. For marine aquariums and ponds the manufacturer recommends 7–10 °dKH.

Fill the test tube with sample water using the syringe and add reagent drop by drop until the colour changes from blue to yellow. In a new aquarium test daily in the first week, then once a week.

The set includes a test tube, the reagent, a syringe, a colour scale and instructions.