Velda Aqua Tests determine the quality of pond and aquarium water quickly and accurately. A useful application is the Pond Test App for smartphone or tablet. After entering the values, you will receive a crystal clear pond diagnosis and tips for improvement from Velda, attuned to your pond situation. The test results are saved to build up a picture of how the pond is developing. pH Testmeasures the degree of acidity of fresh and salt water using a colour chart and comparator. A value above pH 8,5 will stagnate plant growth and a value less than pH 7 is harmful for your fish. GH Testmeasures the general hardness of fresh and salt waterwith an accuracy of 1 °GH. Values less than 8 °GH will slow down the growth of pond plants and may cause acidification, especially in winter. KH Testmeasures the carbonate hardness of fresh and salt water with an accuracy of 1 °GH. Values less than 6 °GH indicate acidification of the pond and stagnation of oxygen producing plants.