Increases the carbonate hardness (KH value) of pond water. This KH value, like the GH value, is expressed in German Hardness Degrees (dH). A sufficiently high value (6 to 8 °dH) counteracts acidification in the pond environment and, through the bound CO2, ensures good development of oxygen plants. The KH value of the water indicates the amount of carbon dioxide-bound calcium and magnesium. The KH value is therefore called the acid-binding capacity of the water. Oxygen plants in particular require a KH value of at least 6 °DH for good growth. At a value below 6 °DH, the acid-binding capacity is low, which can cause the pH value to drop and acidification to occur. The ideal KH value for ornamental ponds is between 6 and 8 °DH. With KH Plus from Velda, this important KH value can easily be increased.