Maintaining the carbonate hardness (KH value) is very important for successful growth of your oxygen producing plants. Mainly because various biological processes in the pond reduce the carbonate hardness. A desired value (6 to 8 ° KH) lowers the acidity of the water and helps oxygen-producing plants to grow and develop, thanks to bound CO2. The Velda VT KH plus water solution is a very effective way to increase the carbonate hardness of your pond. It consists mainly of calcium and magnesium carbonates to provide sufficient nutritious minerals for the oxygen producing plants. This 3.75 L VT KH plus is suitable for treating 22.500 liters of pond water.