Carbonate hardness (KH)

The carbonate hardness shows the pH cushioning capacity of aquarium water. This stabalizes the pH-value.

With a low carbonate hardness the pH-value is unstable and can change repeatedly. The optimum carbonate hardness for the majority of aquariums is between 4-7°dKH. To reduce the hardness we recommend aquavital black peat, or aquavital granu-peat. An increase can be achieved through using calcium contained in stone or gravel (e.g. coral sand or marble stone).