Quick Look

Water quality tests should be conducted monthly and should be more frequent in the summer. Biweekly water tests in the warmer weather let you catch any imbalances before they cause water quality problems or health issues for your fish. Clarity does not always indicate quality. Even if a pond has crystal clear water, there can still be pH imbalances and high contaminants levels. 

You can purchase at-home water quality tests for your pond at Lowes or take a water sample to your local fish retailer. The two most common at-home tests are liquid test kids and dry test kits. When using liquid test kits, you take small samples (vials) of your pond water and add a provided liquid to each sample. A chemical reaction occurs, turning each vial a specific color and, which you then match to a chart to determine the level of what you're testing. Dry tests use the same color and shade method, but instead of using vials, the tests come with strips that you dip into the pond water and then wait for a reaction.

Common Issues


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.

Learn More