Aqua Test Set for measuring pH, GH and KH valuesTo ensure optimum pH, GH and KH values in your pond or aquarium. The test set comprises three beakers for measuring pH, GH and KH values. It can help keep your fish healthy and discourage algae growth. With this set, you can accurately determine what adjustments are necessary to return your pond water to its optimum condition. Usage instructions for pH testing: 1. Rinse out the test beaker several times with the water sample and then add 5 ml of pond