The Importance & Benefits of Lake & Pond Aeration

Many ponds and lakes contain moderate to high amounts of nutrients (namely, phosphorus and nitrogen). Elevated nutrient levels can adversely impact fish, other aquatic organisms and water quality during the summer months. Too many nutrients in ponds and lakes can result in accelerated rates of eutrophication.

Eutrophication is a process whereby ponds and lakes receive high nutrient loadings that stimulate excessive plant growth (algae and aquatic plants). Dissolved oxygen concentrations can severely decline when large amounts of algae (algal bloom) and aquatic plants begin to decompose. In turn, very low dissolved oxygen concentrations can cause other aquatic organisms to die. Nutrients can come from many sources, such as fertilizers applied to agricultural fields, golf courses, suburban lawns, soil erosion, streambank erosion and sewage treatment plant discharges. The symptoms of eutrophication are:

• Low Dissolved Oxygen Concentrations
• Poor Water Clarity (Transparency)
• Algal Blooms (Excessive Amounts of Algae)
• Excessive Quantities of Aquatic Plants (Weeds)
• High Dissolved Metal Concentrations (Iron & Manganese)
• Stress to Fishery and Other Forms of Aquatic Life (Fish Kills)
• Shallowness Due to the Accumulation of Sediments
• Nutrient Releases via Anoxic In-Lake Sediments
• Buildup and Release of Noxious Odors

Just as oxygen serves as the most important element to life on Earth, oxygen also serves as the most essential component to the health of a body of water. Pond aeration and lake aeration are the simple, yet effective, processes of increasing oxygen levels in ponds and lakes and can not only greatly enhance the aesthetic beauty of a pond, but can also improve the natural systems taking place beneath the water’s surface. Aeration creates destratification of the water column, as lakes and ponds typically consist of stratified layers separated mainly by different temperature and oxygen levels. Natural resource and environmental managers are often challenged by problems caused by lake and pond stratification. The main purpose of aeration is to increase and stabilize the amount of dissolved oxygen in the entire water column and this has a widespread effect on many different aspects of pond and lake health.

Aeration systems are generally considered beneficial for warm water fish as they require adequate dissolved oxygen levels and struggle to survive in an oxygen-deprived habitat. Dissolved oxygen is higher in colder water and the process of aeration will distribute cooler oxygen rich water to areas of warmer water and lower dissolved oxygen, thus breaking down the stratification present in the water column. Aeration allows fish to inhabit the entire lake as opposed to only a certain stratified layer, and also improves conditions for organisms that fish prey on.

Water quality is also greatly improved through the use of pond aeration and lake aeration. Under oxygen deprived or anoxic conditions, lake-bottom sediments release various gases and metals that can cause water quality problems. Proper aeration will allow for many of the factors contributing to poor water quality to be released at the oxygen-water interface. Aeration cannot only enhance water quality by stabilizing pH, reducing alkalinity, and removing carbon dioxide, but can also greatly decrease the cost of pond treatments.

Aeration can also reduce the amount of algae in ponds and lakes through a variety of processes. Through aeration, algae spores can be mixed towards deeper lake and pond areas, reducing the amount of time it is exposed to valuable sunlight and availability to grow. Higher dissolved oxygen levels can also lead to a shift from harmful blue-green algae to less-noxious green algae.

Another important benefit of pond aeration and lake aeration is the reduction of Phosphorus (P) concentrations in ponds. Phosphorus is needed to support algae blooms, and once phosphorus enters a pond’s ecosystem it is very difficult to remove. Aeration accomplishes this by using an oxidation reaction which causes the phosphorus to bind with naturally occurring iron. Once bound to the iron, this new form of phosphorus precipitates into the sediments where it remains unavailable for plant and algae growth as long as sufficient levels of dissolved oxygen are maintained.

Overall, aeration will provide many different benefits to pond and lake ecosystems. Besides enhancing pond fish habitats, improving water quality, reducing algae, and removing phosphorus, aeration can also break down unwanted bacteria, help with mosquito problems, and remove foul odors from a pond — all by circulating the water and adding dissolved oxygen. Pond aeration is available through a variety of different means, whether through surface aerators like floating fountains, or through bottom fed aerators using compressors and air diffusers. Now with an understanding of the benefits of aeration, it is time to decide what type(s) and size(s) of aeration are needed for your specific waterbody. 

Professional pond and lake manager have a number of scientifically proven tools to properly manage eutrophic water bodies. One of the most common tools in their toolbox are pond and lake aerators for pond aeration and lake aeration. Pond aeration is the process of adding more air or more specifically, more dissolved oxygen into the water. Pond and lake aerators are frequently implemented with other lake management restoration practices such as applying algaecides and aquatic herbicides to control nuisance quantities of algae and aquatic plants, respectively.

The two most common methods for aerating ponds and lakes are installing water fountains and diffused-air aeration systems. Of the two, diffused-air aeration systems are much more cost-effective and require far less maintenance. In many instances, water fountains will not completely circulate/mix ponds and lakes if their water depths exceed five feet. In addition water fountains are prone to clog if substantial amounts of filamentous algae are present.

Many pond and lake owners find water fountains very attractive as a water feature. For these individuals, Aqua Link recommends installing both water fountains and diffused-air aeration systems. This is especially true when highly eutrophic pond or lake conditions exist. Overall, the water fountains will primarily serve as attractive water features, while the diffused-air aeration systems will be responsible for providing the bulk of the water mixing and aeration.

Diffused-air aeration systems for both pond aeration and lake aeration like the Hydro Logic AirLift and AirLift XL series can significantly improve water quality and ecological health of ponds and lakes. Increased dissolved oxygen concentrations allow for decreased amounts of available nutrients throughout the water body. This translates into lower amounts of algae resulting in improved water clarity. Aeration also allows for less noxious, poisonous gases (methane and hydrogen sulfide) to be generated. The end result is healthier ponds and lakes for fish and all forms of aquatic life.