The stabilizer for the pH

The carbonate hardness is the stabilizer for the pH. With low carbonate hardness the pH is unstable, and can change rapidly again and again. The optimum for most aquariums and ponds is 4 – 8 °dKH.

To reduce the hardness, we recommend AQUAVITAL BLACK PEAT or AQUAVITAL GRANU-PEAT. To increase the hardness, place stone or gravel containing calcium (e. g. coral sand or marble stone) in the water. Products which contain carbonates, or dissoved baking soda, can also be added to the water to increase carbonate hardness.