Maintaining the mineral water hardness is essential for your plants to flourish, as soft water stops biological processes and causes the water environment to become acidic. A pond can only be stable and healthy if the total mineral hardness is at least 8° DH. The Velda mineral plus pond additive is a very effective way to increase the mineral hardness of your pond. It is essential for the growth of aquatic plants and the development of microorganisms, and of course to adjust the mineral balance. This 1500 ml bottle of Velda mineral plus is suitable for treating 9000 litres of pond water.