The health and beauty of all pond life depends on the quality of water added to the pond. Many tap water supplies used to fill garden ponds contain chlorine. While chlorine makes water safe for drinking it is highly toxic to pond life. Chlorine destroys fish gill tissue preventing the uptake of oxygen and the release of carbon dioxide resulting in fish death. Even low levels of chlorine irritate delicate skin tissue on frogs, snails, and salamanders.
Certain metals such as copper and zinc are essential to pond life metabolism. But in elevated and unnatural levels they become toxic and are classified as toxic "heavy metals", these include lead, tin, copper, zinc, and manganese. Heavy metals sometimes enter tap water via lead and copper pipes as well as the solder used to join the pipes. Airborne pollutants can deposit heavy metals in the pond. Heavy rains carry airborne metals in to the pond where they may accumulate to toxic levels. Acid rain causes "unreactive" metals lying dormant in the pond to become toxic.
Instantly neutralizes chlorine, copper, lead and zinc, as well as other heavy metals found in tap and well water, all of which may be toxic to fish and plants. One ounce treats 600 US gallons of pond water.