Water fountains are usually floating devices that propel water several feet into the air. Fountains provide some aeration but usually only at the surface and a modest distance around the fountain. Fountains are popular additions to golf course ponds, city park ponds, and urban ponds where aesthetics is deemed more important than aeration. If aeration is your primary concern, other aerator types are more effective. Fountains are typically located in a central location in clear sight of the most common viewing angles of the pond.

Vertical pump aerators use a submerged motor and propeller to lift a dome of water a short distance into the air. Like fountains, vertical pumps are usually mounted to floats that can be secured in place by wires or ropes connected to anchoring devices at the pond bottom. Vertical pumps create good surface agitation with good aeration efficiency. They are viable options in fairly shallow ponds because they can operate in shallow water, but they also only aerate surface water and a modest distance around the pump. Vertical pumps are good choices for shallow ponds where surface aeration is the primary concern. Vertical pumps are typically centrally located and evenly distributed around a pond to ensure complete coverage of oxygenated water.

Paddle wheels are the aerator of choice for most pond aquaculture operations because they add more oxygen per dollar of electricity than other types of aerator in relatively shallow ponds. They consist of a motor mounted to a floating platform with a large rotating drum or cylinder ringed with broad metal or plastic flaps that splash into the water and lift it into the air. Paddle wheels operate at fairly high RPM’s and they can create considerable circulation at the surface which helps distribute the oxygenated water to other parts of the pond. In rectangular ponds, a single powerful paddle wheel can be located on one of the long banks facing straight across the pond towards the other long bank to create two areas of circulation which can keep the entire pond aerated. While highly effective, paddle wheel aerators are typically expensive, heavy, and not considered one of the more attractive options in aeration/circulation.

Circulators are designed to move large volumes of water. Some aspirated models inject bubbles into the moving water to accomplish both aeration and circulation. Circulators can come in floating and submersible models with motors that turn boat-like propellers below the surface. The angle of the propeller can be adjusted to fit the depth and circulation needs of the pond. Submersible models can be mounted to the legs of fishing piers, boat docks, stumps, or beneath floating platforms. Circulators are particularly helpful in preventing thermal stratification in ponds, which can reduce or eliminate annual turnovers altogether, and forcing oxygen down to deeper parts of the pond.

Diffusers consist of air blowers mounted on land near the pond filling air hoses connected to bubble diffuser pads anchored to the pond bottom. The diffuser pads release a stream of small bubbles that release oxygen and create vertical current as they rise. Diffusers are the most effective tool for aerating and circulating deep water (10+ feet deep). The drawback to diffusers is that they are not very effective in water less than about 8 to 10 feet deep. Diffusers are excellent options for preventing thermal stratification in deep ponds and reducing the threat of annual turnovers. It is common for one air blower to supply air to several diffusers distributed around the pond for complete circulation and aeration. Solar and wind-powered diffusers are available. Solar models feature solar panels and some have batteries allowing them to operate at night. Wind models include large windmill towers. The wind models work only when the wind is blowing. Solar and wind-powered diffusers are good options if electricity is not available at the pond site and they are free to operate after equipment purchase and installation plus regular maintenance, but they are not as powerful or effective as their hard-wired counterparts. Diffusers are most effective when operated continuously, and the solar and wind-powered diffusers typically go offline when the aeration is needed most (at night and when the wind is not blowing).