Pond Aerators vs. Pond Fountains

Choosing the correct type of aquatic feature ensures the health of aquatic life in your pond and can improve the pond's aesthetic appeal. Ponds that are improperly managed can suffer die offs, creating an unsightly, foul-smelling mess. Aerators are used to ensure that the pond's aquatic life has the oxygen it needs to survive. Pond fountains are generally decorative and provide little benefit for the plants and animals living in the pond.


Pond aerators are designed to recirculate pond water and increase the amount of oxygen suspended in the water. This action ensures that the aquatic plants and animals living in the pond have adequate access to oxygen and prevents the pond water from becoming stratified. "Stratified," or "stratification," means the bulk of the pond's heat and oxygen remain near the water surface. Several kinds of aerators can be used to prevent stratification, including diffusers, paddle wheels, pump sprayers and vertical pumps. Diffusers are designed to pump and diffuse air into the bottom of the pond, and paddle-wheel models stir the water with a large paddle wheel. Pump-sprayer and vertical-pump models use submerged water pumps to draw water from the bottom of the pond and spray it over the pond surface.


Fountains improve a pond's aesthetic appeal and recirculate the water near the pond's surface. Fountains are generally ineffective at preventing stratification because they do not recirculate the water near the bottom of the pond. In most cases, water near the pond's surface usually has enough oxygen to support the plants and animals found near the water surface. Pond fountains placed too close to the pond's bank can contribute to erosion of the bank over time. A pond's fountain should be in the middle of the pond, and the waves the fountain creates should dissipate before they reach the pond's edge.

Pond Care

In ponds that are more than 8 feet deep, the upper 4 to 6 feet of water heats more rapidly than the water near the pond's bottom. The difference in temperature between the top and bottom of the pond creates layers of water with different densities that do not mix. The oxygen in the water of the lowest layer becomes depleted over time, killing all plants growing near the bottom and causing them to rot. Once the temperatures decrease or a storm mixes the upper and lower water layers, a turnover occurs. Turnover forces the rotting plant matter to the surface, where it depletes the oxygen levels in the rest of the pond. Rapid turnovers can completely kill all fish and plants in a pond.


Ponds with a large surface area or an irregular shape often require more than one aerator to recirculate water and oxygen properly in the entire pond. The most important time of the year to provide aeration for your pond is during summer, when the surface water is heated rapidly during the day.

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Daniel Thompson


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