• Simple and reliable monitoring of the water values in aquariums/ponds. Determines the ideal general hardness in freshwater aquariums and ponds
• Colour change test: fill plastic cuvette with sample water, add reagent drop by drop until colour changes from red to green. Number of drops = level of general 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 GH quick test, incl. one reagent and plastic cuvette. Reagent refill separately available

Healthy aquarium/healthy pond with conditions close to nature

The right water values are dependent on the fish stock and the plants in the aquarium/pond. Even if the water looks clear it can be contaminated. With bad values diseases or algae can appear in the aquarium/pond. To maintain a healthy aquarium/pond with conditions close to nature it is important to check and adapt the water values regularly.


For each water analysis JBL provides water tests in the form of quick tests or colour change tests. These determine a certain value or several values in one go. With these water tests you can recognise algae problems and negative nitrate, nitrite, potassium, magnesium values etc.


Why test?

Depending on origin and consistency of the subsoil, water may contain varying quantities of alkaline earth salts, usually in the form of calcium and magnesium salts. General hardness, by definition, is the sum of calcium and magnesium ions. Most fish and plants thrive well at a general hardness of between roughly 8 and 20°dH. Excessive total hardness values, should, however, be counteracted by the appropriate measures.


JBL Online Laboratory

Regular control for a healthy aquarium/pond with conditions close to nature. Enter your water values into the JBL Online Laboratory and get an in-depth analysis of your values within seconds.


Recommended general hardness values:

Freshwater aquarium (community aquarium): 8-25 °dGH

Lake Malawi/Lake Tanganyika aquarium: 5-20 °dGH

Plant aquarium with few fish (aquascaping): 3-10 °dGH

Marine aquarium: not measurable with GH test because GH too high. Please test calcium and magnesium separately Pond: 6-20 °dGH