Water in rainforest rivers is conditioned by leaf tannins, humic and organic acids. Some leaching of ground minerals also occurs. These conditions are natural disease inhibitors for fish. The water is soft, usually below 50ppm hardness and a pH between 5.5 and 6.5. Amazon Water Conditioner recreates these same conditions in an aquarium. The result is brighter and more active fish, with a high resistance to disease.