Water test to quickly and easily check aquarium water quality in 60 seconds: test strips measure pH, carbonate hardness (KH), general hardness (GH), nitrite (NO2-), nitrate (NO3-) and chlorine (Cl2) Water test to check the six most important water values in one step Measures the pH, general and carbonate hardness (GH + KH), nitrite (NO2-), nitrate (NO3-), and chlorine (Cl2) Full information and tips on possible countermeasures can be found in the instructions for use Tip: with the Tetra Aquatics app you can determine water values quickly, reliably and easily using your smartphone