Measures: pH High, pH Low, Ammonia, Nitrite

Correct water conditions are essential for the health and development of both fish and plants. A stable pH, maintained at the natural level for specific aquarium inhabitants, is essential for their well being and therefore should be checked regularly.
Ammonia, which is toxic for fish, is regularly introduced into the aquarium by fish waste. A functioning Biological Filter will convert the Ammonia to Nitrite and thereafter to Nitrate, which are less harmful. Regular testing for Ammonia & Nitrite will provide a positive indication that your Biological Filter is functioning correctly. The solubility of CO2 in water is affected by the Carbonate Hardness (KH) of the water.

All plants and many fish species are dependant on a specific General Hardness (GH) for their well being. Therefore both GH and KH should be monitored regularly. Chlorine is harmful to fish, plants and nitrifying bacteria. Use the chlorine kit to ensure that only chlorine free water is added to your aquarium.