Roan Fishery
Roan Fishery, South Yorkshire

Lake Aeration

When choosing which type of aerator to use for aquaculture ponds, it is helpful to know some basic facts about aeration.

Without sufficient oxygen, aquaculture animals will become stressed, sick, and possibly die. Even when a good quality water source is available, the large inputs of nutrients and organic matter that result from feeding and animal waste can lead to a low level of dissolved oxygen in the pond. Good mechanical aerators can effectively replenish the level of dissolved oxygen in ponds. Choosing which type of aerator to use is very important, however, because numerous studies show that certain types of aerators are better than others.

Aerators perform two basic functions: they oxygenate water and induce water circulation. Both functions are important in pond aquaculture. Pond water normally contains plenty of dissolved oxygen during daylight hours, but in ponds with high feeding rates and abundant phytoplankton blooms, dissolved oxygen concentrations may decline to dangerously low levels at night. Aeration can be used during the night to stabilize dissolved oxygen concentrations within safe ranges.

A moderate degree of water circulation in ponds is beneficial: it prevents stratification of the water to provide more uniform water quality. Also, organic matter from uneaten feed, faeces, and dead plankton settles to pond bottoms and decomposes. This can lead to anaerobic conditions in the superficial layers of bottom sediment with the release of toxic microbial metabolites in the overlying pond water. Induced circulation of pond water increases water flow and delivery of dissolved oxygen to the surface of the sediment to lower the possibility of anaerobic conditions at the sediment-water interface.

Because of better water and soil quality in response to aeration, fish eat better, have greater resistance to diseases, suffer less mortality, and achieve better feed conversion efficiency in aerated ponds than in ponds without aeration.

An aerators two basic functions:

1. Oxygenation
Some controlled experiments have compared the difference between aquaculture ponds that are aerated daily and ponds that are not aerated at all. These experiments prove conclusively that aeration is extremely helpful, if not absolutely necessary.

2. Circulation
The greatest influence of water circulation on oxygen concentration is the blending of surface water with subsurface water. During daylight hours, surface waters in ponds are often supersaturated with dissolved oxygen, while water at greater depths often have little dissolved oxygen. Oxygen produced by photosynthesis of the phytoplankton at the surface can be conserved by mixing it and distributing it equally throughout the pond water. In this way, mixing pond water can unify the amount of dissolved oxygen at all levels of the pond. In addition, because of numerous biological factors, the total net-dissolved oxygen content of a pond can even be slightly increased from water circulation alone. Water circulation prevents thermal, oxygen and chemical stratification, helping to make the entire pond volume habitable for aquatic animals.

The Airflo aerator mixes pond water much more thoroughly and effectively than do vertical-pump aerators (commonly known as mushroom, or impeller-type aerators) and paddle wheel aerators. A vertical-pump aerator does not create a horizontal flow, and therefore "recirculates water in the zone immediately around it." Paddle wheel aerators create a flow on the pond surface only, making them much less effective than efficient as the Airflo at mixing surface water with subsurface water.

Another important result of circulation is to treat the pond bottom soil. Clean pond bottom soil is one of the essential ingredients for successful aquaculture. Even when a good quality water source is available, the large inputs of nutrients and organic matter that result from feeding and animal waste can lead to poor bottom soil conditions.

Soil condition in aquaculture should be given the same degree of consideration as water condition. Just as there is a condition of equilibrium between the water and the air, there is also a condition of equilibrium between the water and the soil. Water quality can be greatly effected by its interaction with the soil. Many of the suspended particles found in the water are derived from its contact with the soil.

Solids in the water settle to the bottom, creating a layer of sediment. This layer of sediment is different than, and should be distinguished from, the original pond bottom soil. If this sediment is allowed to accumulate at the pond bottom, the organic matter contained in it will decompose and create anaerobic conditions at the soil surface (the soil-water interface). Toxic metabolites such as hydrogen sulfide will then be released into the water. A method of aeration that "produce[s] uniform, gentle water currents over pond bottoms to suspend fresh organic particles without suspending mineral soil particles" is ideal. If suspended in well-oxygenated water, organic particles will decompose aerobically without the associated production of toxic metabolites.

Because the Airflo aerator moves water horizontally at depth, it is able to lift sediment off the pond bottom without eroding the soil. (Other submersible aerators, such as the Aire-o2, move water at a downward angle and therefore "suspend mineral soil particles" rather than only "organic particles" like the Airflo is capable of doing). The floating sediment is then mixed with the oxygen-rich pond water, causing it to decompose. Neither paddle-wheel nor impeller-type aerators are able to effectively carry out this essential process.

Mechanical aeration is a proven technique for increasing the dissolved oxygen content in ponds. In addition to oxygenating, an aerator must also circulate the water to eliminate temperature, chemical, and oxygen stratification between various depths of the pond water. The aerator must work at a depth sufficient enough that its oxygenating and circulating efforts can treat the pond bottom soil, keeping it oxygenated and free of deadly toxins that can pollute the water and harm or kill aquatic animals, but it must do so without eroding the pond bottom soil.


AIRFLO Lake Aerator Air Injector

From £495.00 Incl. free delivery

AIRFLO Lake Aerator Air InjectorAIRFLO are really four machines in one since they provides very high levels of oxygenation by introducing up to 2 cubic metres of air per minute into the water using the venturi principle, as well as good circulation, de-stratification and de-gassing

Since the motor system can be angled to point upwards or downwards and the depth varied by adjustment of the two snorkel tubes that support the motor below the float system, any one or more of these benefits can be increased so as to help the customer with his or her particular individual needs.

The units are portable, easy to install and are available in a choice of power factors, 1 hp, and 1.5 hp, according to specific type, and a choice of 220/240v single phase or 380/415v three phase.

These versatile aerators provide a simple, portable and low cost answer to water circulation and de-stratification problems, in both large and small ponds and lakes.

They can be used effectively to resolve many problems in general fish keeping and are good at helping control weed/algae and fighting the formation of ice in winter.

Please Note: These are the most reliable aerators on the market, The lake aerators we stock are made by Euro Tech. They are small easy to move around but extremely efficient in what they do.

Efficient and thorough aeration over a large portion of the water volume:
The air introduced into the water by paddlewheel method covers only a very small portion of the water area, and the air bubbles are all near the surface. Therefore, this type of aeration does not generate a large quantity of absorbed oxygen in the water. Impeller (mushroom-type) aerators produce similar results.

The Airflo submersible aerator introduces air directly into the water at depth, enough to saturate 15 cubic meters of water with oxygen every minute. At the same time, the 2800rpm propeller causes the oxygenated water to flow at least 35 meters out in front of the aerator. As the above picture demonstrates, this results in absorbed oxygen being dispersed equally over a very large portion of the water volume. The level of absorbed oxygen created is many times greater than that created by paddlewheel and impeller aerators.

Adequate circulation and destratification:
Paddlewheel and impeller (mushroom-type) aerators are only able to aerate at the water's surface. They are therefore unable to create a flow of water at lower levels. The oxygen they add to the water is limited to a small area near the surface. This often results in situations similar to that illustrated in diagram A above: aquatic animals are forced to concentrate themselves into the small areas of oxygenated water that these aerators create, competing for the limited oxygen there.

The Airflo aerators high-speed propeller creates a flow of water at depth. This works effectively to mix the different levels of water together throughout the pond. The pond water thus becomes uniform in temperature and chemical makeup at all depths and at all positions of the pond. When this flow of water is combined with the Airflo’s high oxygen-absorption rate, the result is that every area of the pond is equally hospitable to aquaculture animals. Instead of competing for oxygen in small areas of the pond, they freely swim around like in diagram B above.

Cleansing of the pond bottom and decomposition of organic particles:
The pond-bottom soil greatly affects the quality of pond conditions. Aquaculturalists know that clean pond-bottom soil is as important as clean water. Even if the source water is excellent, pollutants are created from uneaten food and waste which accumulate and settle on the bottom. This creates a layer of sediment that produces deadly gases and toxic pollutants. The most effective way to deal with this sediment is to lift it off the pond bottom and treat it with oxygenated water.

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Geyser Splash Lake Surface Aerator

From £495.00 Incl. free delivery

Geyser Splash Lake Surface AeratorWith high demand from anglers these days, fisheries are forced to stock more and more fish, resulting in very low oxygen levels at certain times of the year.

This can stress the fish out and could even cause a fish kill in your pond or lake. Not only will the splash aerator prevent this, it will keep the fish feeding throughout this period resulting in greater fish growth rates.

The GEYSER SPLASH is a lightweight durable, efficient and economical aerator. We are confident it will improve your water quality and thereby give you economic benefits. This range of aerators are available in two power ratings, 0.5 hp , 1 hp 220/240v single phase or 1 hp 380/415v three phase. All Geyser aerators draw up colder water in the summer and warmer in the winter so as to maximise the aeration effect by de-stratifying, de-gassing and oxygenating. They are very efficient aerators, providing very high levels of oxygenation for low power consumption and modest cost.


Geyser Splash Lake Fountain Aerator

From £495.00 Incl. free delivery

Geyser Splash Lake Fountain AeratorIdeal for ornamental lakes and golf courses, the Geyser Spring is a lightweight durable, efficient and economical aerator with the added advantage of being a decorate aerator. We are confident it will improve your water quality and thereby give you economic benefits.

This range is available in power ratings, 1.5 hp in 220/240v single phase or 380/415v. All Geyser aerators draw up colder water in the summer and warmer in the winter so as to maximise the aeration effect by de-stratifying, de-gassing and oxygenating. They are very efficient aerators, providing very high levels of oxygenation for low power consumption and modest cost with the advantage of a fountain effect.

The main functions of both aerators are:

  • The GEYSER SPLASH aerator directs the water from the bottom to the surface of the pond, mixes the water with air, and then circulates the water at a rate of up to 5120 litres of air a minute. This rate of aeration is 7 to 8 times greater than of traditional aerators.
  • The stirring action of the GEYSER’s high speed propeller splashes and mixes water at a high speed fully oxygenating the water.
  • Because 21% of air is oxygen, the above process will decompose poisonous substances in the water.
  • This aerator creates a huge spray to cover a large area of the ponds surface, spreading oxygen evenly through the water.
  • Since the aerator creates an ample supply of oxygen it is especially suitable for intensive aquaculture farming.
  • High quality stainless steel and industrial plastic are the only materials exposed on the machine giving it a strong resistance to the corrosive effects of seawater and pollutants.
  • It is very suitable for the areas in freezing winters. The effects of the machine cause the ice to melt.

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The ECO aerator Venturi Aerator

£40.00 Incl. free delivery

The ECO aerator Venturi AeratorECO Aerator Provides:

  • Circulation without further energy.
  • Water enriched with air or pure oxygen.
  • Has been made in order to use water delivery more economically and in the best conditions, that is oxygenized and stirred.
  • To make the dissolution process faster.
  • To transform the unwanted gases in the water into small bubbles and eliminate them.

The Eco Aerator is a simple venturi device that can be fitted to the outlet end of any pipe or pumped water line to provide the added benefits of oxygen to the water. Used in aquaculture tanks and ponds, ideal for situation’s that require aeration and water movement at the same time.

The round shape of The Eco increases the oxygen transfer due to longer contact time between air and water. Like any venturi , the Eco will require water pressure in order to enable it to draw air into the venturi housing. The Eco comes standard with a series of 3 different sized nozzles allowing the air to water mixture ratio to be selected on site.

The Eco Aerator is an ideal addition to small rearing tanks and ponds and can be used individually or in multiples attached to a common manifold in order to suit the environment in which it is used.

An individual Eco Aerator comes complete with a set of outlet nozzles sized, 11mm, 8mm and 6mm) suitable for a water flow of 100 litre/minute (or26 gallons/minute), 50 litre/minute (or 13 gallons/minute), 30 litre/minutes (or 8 gallons/minute), as well as a 1 inch water inlet hose fitting and a 3/4 inch air inlet hose fitting.

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Subflo Water Circulator

From £495.00 Incl. free delivery

Subflo Water CirculatorThe SUBFLO submersible mixer blows air directly into the water at depth in the form of micronized bubbles, at rate of 22,500 litres of air per hour.

This rate of aeration is 7 to 8 times greater than for traditional aerators. The stirring action of the submersible mixer’s high-speed propeller draws air into the water and mixes water at a high speed, fully oxygenating the water. Because 21% of air is oxygen, the above process will cleans and purify the pond’s water within a matter of weeks (granted enough aerators are used for the given condition and volume of the pond’s water). This aerator creates a flow of water at depth to a distance of 35 meters, spreading oxygen evenly throughout the entire pond’s water volume. Since this aerator creates an ample supply of oxygen, it is especially suitable for EM breeding. High-quality stainless steel and industrial plastic are the only materials exposed on the machine, giving it a strong resistance to the corrosive effects of seawater and pollutants. It is very suitable for the areas in freezing winters. The effects of the machine cause ice to melt.

The Subflo Aerator is ideally suited to long canal type fisheries and stock pools. Its effect can be over 70m in front of the machine, with a width of around 15m.

Water circulation is beneficial as it helps destratify deeper waters, breaking up the thermal layers. This helps ensure a uniform temperature and dissolved oxygen distribution.

The Subflo is excellent at keeping large areas of water ice free, and can be used to create artificial rivers.Often in summer additional aeration is not required during the daytime, as submerged aquatic plants and algae can provide the necessary oxygen through the process of photosynthesis (though the reversal is true during the hours of darkness or cloudy weather, as the algae will consume oxygen through respiration). However by mixing the saturated upper layers of water, the dissolved oxygen can be distributed more evenly throughout the water body. Circulating water can also have a positive impact on the amount of silt build up, as the suspended particles are exposed to the oxygen rich water, which speeds up the decomposition process.

Well mixed waters reduce the release of nutrients from the sediments and disperse nuisance algal blooms. Also the use of aerators promotes the growth of the biologically friendly aquatic fauna which compete against the algae.

The Subflo 1.0HP is a water circulator used in applications to provide mixing, destratification, and circulation of a water body. The unit, when in operation, maintains constant water movement from the surface to the bed of a water body. Potential applications for Subflo 1.0HP include effluent mixing, promotion of channel flow and provision of effective circulation to destratify water bodies. The submersible motor unit provides direct drive to twin propellers (180 mm in diameter) rotating at 1400 RPM.

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12V Emergency Aerators

£925.00 Incl. free delivery

12V Emergency AeratorsFinally, you can get rid of the fear of a fish kill in remote areas or those brought on by sudden condition changes.

With the 12V Emergency Aerator, you will never have to be at the mercy of mother nature when fish kills threaten ponds long distances from power or those rapidly changing conditions that can bring upon a fish kill in hours. This revolutionary 12V, DC powered aerator will save you and your fish in a pinch.

Powered by a common, 12V deep cycle battery ( not supplied ), the 12V Emergency Aerator can provide you with nearly 5 hours of continuous operation on a single 100 amp hour battery, while the 100w solar panel kit keeps the battery topped up running time would be dependent on the sunlight and location , providing life sustaining oxygen to the pond and its inhabitants. The light weight and compact design of both the aerator and solar panel also lends themselves to lightning fast installs for immediate aeration needs.

Portable Mono Folding Solar PanelEach unit comes complete with 12V, DC aerator motor with performance prop and prop guard, 10metres of power cord that includes alligator clips for the battery connection and ON/OFF toggle switch, and a float with mounting hardware and two 50’ anchoring ropes. 100W Portable Mono Folding Solar Panel with an integral charge regulator and cables complete with battery clips.

The powerful, 275 watt motor provides excellent oxygen transfer and can provide short-term aeration in an emergency and/or harvesting aeration in much larger ponds.

Don’t waste another day dodging the fish kill bullet hoping your pond will be spared. Purchase a 12V Emergency Aerator kit and rest easy at night knowing you can save your fish in a moment’s notice.

The main functions of the 12V Emergency Aerator is:

  • Powerful: 275 watt motor to supply excellent oxygen transfer
  • Efficient: Up to 5 hours on a single, 100 amp hour deep cycle battery
  • Rugged Motor: Durable finishes on all materials, internal auto-reset thermal overload protection, stainless steel motor shaft, sealed ball bearings, long life brushes, and mechanical seals.
  • Portable: Light weight and compact design, perfect for emergency applications
  • Operates in as little as 15” of water
  • 1 year warranty

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Aerators For Sale

We have a number of products that dramatically agitate high volumes of water at all levels to maximize exposure of water to the air for valuable gas exchange, greatly improving your pond or lake aeration.

Please click on the links below for more information.

AIRFLO Lake Aerator Air Injector

Geyser Aerators

ECO Aerator Venturi

Subflo Water Circulator

12V Emergency Aerators