Why are my pond fish gasping for air at the surface of the water?

If you see your fish gasping, or piping, for air at the surface of your pond, immediate action is required. Piping is when fish breathe rapidly at the water surface, often with part of their mouth exposed above the surface. Your fish are not trying to say hello, they are trying to tell you theyre in survival mode. Your fish are at the surface trying to breathe. There’s a dire lack of oxygen in the water and you need to act. Fast. 
Low levels of oxygen can be the result of several factors including but not limited to lack of aeration, lack of aquatic plants, overfeeding, overstocking, or overall poor water quality. Regardless of why, lack of oxygen causes fish stress, which slows their immune systems and leaves them vulnerable to parasites and disease. Avoid this unfortunate situation by aerating the water and keeping its quality in check. 
Fish need varying amounts of oxygen depending on the season. In winter fish need less because they are hibernating but during summer months, when fish are most active, they demand a higher amount. With in the warmer temperatures of summer, water holds less dissolved oxygen leaving aquatic life competing for the little that remains. This is why supplemental aeration is so important. You can also add oxygenating pond plants, which naturally release the essential element into the water throughout the day. Be sure to keep your pond pumps and fountain nozzles running 24/7. You can add an aerator, a waterfall, or spitter to make sure the oxygen levels are sufficient. 
Poor water quality can lead to fish gasping at the pond’s surface, so routinely check your filtration system and use a pond water test kit to evaluate the ammonia and nitrite levels. Using water treatments, like our Pond Cleaner Tablets, add beneficial bacteria, while Chlorine Remover Plus and Water Clarifier eliminate harsh chemicals and help to ensure excellent water quality for healthy fish. 
If your fish are gasping for air, quickly oxygenate the water by turning on a hose or any other water pump and spraying the water in the air, so it collects oxygen and lands in the water. This is a temporary solution and should be replaced with more permanent aeration. Doing a partial water change is also recommended during this time. If the water has more than a 10°F temperature difference, perform the water change over a period of several hours. 
Once youve come to the rescue, it's important to determine what caused the sudden loss of oxygen. Often, depleted oxygen levels are due to excessive algae blooms, dead organics, excess nutrients from storm water runoff, and fish disease/parasite. Checking the pond site and using a test kit will help determine the cause and the steps to fix the problem in your pond.