Fish and plants need a stable pH that remains in the 6.5 to 9 range. A fish's natural pH is around 7.4, so anything too far away from this can stress their bodies. If the pH level falls below 6.5, the water becomes too acidic for the fish to live.
Fish naturally produce ammonia, but high levels are very toxic to pond life. Ideally, there should be 0.0 ppm of ammonia in the water. Even 0.25 ppm could be harmful.
Bacteria in the pond break down ammonia into nitrite. There should be less than .25 ppm of nitrites in the water, as nitrite can cause severe health problems to fish and other pondlife.
Nitrite is broken down into nitrate by bacteria in the pond. Nitrate levels should be between 20 ppm and 60 ppm, and it is less harmful than nitrites.
Tip! Water Treatments can help solve common quality issues such as cloudy, murky water.