Last Updated on March 24, 2020 by Aiden Lindow

Pond Aeration 

Over the past 10-20 years, the construction of ponds has become very popular as well as environmentally friendly methods for cleaning and maintaining healthy ecosystems.

Before you build a pond, it makes sense to calculate the costs of its construction and maintenance, to consider how to maintain a healthy environment for as long as possible. 

One of the easiest and most economical ways to maintain a healthy ecosystem in a pond is through water aeration.

Aeration is the process of adding oxygen to water.

Maintaining the required concentration of oxygen dissolved in water, one of the most important, if not the most important indicator of the quality of water in your pond. 

It helps to decompose the remains of dead plants and other nutrients present in your pond. 

The decomposition of bottom sediments is carried out by microorganisms in the bottom layer of water at the interface between two media: 

water and soil, as well as in bottom sediments at a depth of several centimeters. 

This decomposition can occur under aerobic or anaerobic conditions. 

Aerobic decomposition requires a constant flow of oxygen. 

The process is as fast as possible with the concentration of oxygen in water at the saturation level.

The decomposition rate of organic substances under anaerobic conditions (in the absence of oxygen) is slower than under aerobic conditions, and the final products are organic substances such as alcohol and foul-smelling organic acids (sulfuric, dung smell). 

In other words, in anaerobic environments, environments without oxygen, decomposition is slower and less complete than in aerobic ones, where the main end product of decomposition is carbon dioxide. 

Thus, the more we increase the decomposition efficiency by adding oxygen to the water by aeration, the fewer nutrients will remain for algae bloom and too rapid growth of aquatic plants.

Under natural conditions, oxygen enters the water during wind, rain, spraying, and mixing of water from an inflowing stream or waterfall and due to the process of photosynthesis that occurs in aquatic plants. 

Since many biogenic (nutrient) substances enter the pond from outside, for example, with polluted effluents, dust from construction sites, mowed grass and falling leaves, the need for oxygen for their decomposition increases. 

Warm water contains less dissolved oxygen, which explains why in the summer the water in the pond “blooms” faster, fish can die in it, and water plants become sluggish.

Aeration can help nature maintain the natural need for oxygen dissolved in water and activate life in your pond. 

An increase in the concentration of oxygen dissolved in water during aeration leads to a balance of biological processes in the pond. 

Aeration also activates the mixing of water in areas with low circulation (in which algae may not actively grow) and facilitates the mixing of water throughout the pond. 

In short, aeration helps purify stagnant water in ponds and improves water quality.

 

Pond Aeration

 

What affects the concentration of oxygen dissolved in water?

Atmospheric pressure, salinity, purity of water and biological oxygen demand – all this affects the natural concentration of oxygen in the water. 

The amount of oxygen added to the water through the aeration process depends on temperature, altitude, and salinity. 

Colder water contains more oxygen than warm; the water at higher levels or with higher salinity has a lower level of oxygen saturation. 

To achieve saturation, the oxygen concentration can be increased either by photosynthesis or by adding oxygen from the outside.

Adding oxygen to the water of the pond using various aeration devices can:

  • Eliminates seasonal changes in oxygen levels in spring and autumn
  • Prevent plant wilting
  • Improve overall water quality
  • Speed ​​up the decomposition of organic matter
  • Reduce the amount of phosphorus that activates plant development
  • Reduce thermal and chemical separation of water
  • Create circulation flows that could create favorable conditions for algae competing with blue-green algae reduce the flowering rate of algae

Due to evaporation, reduce the concentration of carbon dioxide in water, which negatively affects the development of plants

 

Pond aerators in summer

On hot summer days, there is a particular lack of oxygen in the pond. According to the laws of physics, the higher the temperature of the water in the pond, the less oxygen can dissolve in the water. 

And this directly affects the fish stock. And for some fish species, depletion of water by oxygen is detrimental. 

To save your valuable fish, you need an aerator compressor for the pond.

Keeping Your Pond Cool In The Summer will also allow more oxygen to dissolve into the water.

 

What are the features of pond aeration in winter?

In the winter, when the surface of the reservoir is ice-bound, the fish also suffer from a lack of oxygen. 

In addition, they are adversely affected by harmful gases released from the sludge at the bottom of the reservoir. 

And in this case, a stone placed in shallow water – a diffuser or diffuser of a compressor aerator for a pond, enriches the water with oxygen and creates a hole in the ice above the diffuser. 

That is, in this case, the aerator for the pond in winter acts as an anti-icer. 

In winter, it should be insulated. And besides, such an aerator for a pond in winter should work continuously. 

If an emergency shutdown occurs, it must be warmed up and restarted.

My favorite pond aerator is the Tetra Pond Air Pump. IT works great and I have never had a problem with them.

How to choose garden aerators for a pond?

To select such a device, you need to know the volume of water in the pond. 

On the original packaging of each type of aerator for ponds, it is indicated on what approximate volume of water in the pond this aerator is intended. 

The same information is indicated in the instruction manual. 

In addition, it should be kept in mind that the deeper the diffusers, air atomizers, the larger the pond aeration zone. 

But on the other hand, the deeper you install diffusers, the less air will be released at that depth. 

The maximum possible immersion depth is indicated in the instructions for the pond aerator is 10 meters of water. Very few ponds go below the depth of 3 meters.

For some devices for pond aeration, tables of the dependence of the amount of pumped air on the immersion depth of the diffusers are given.

 

What does the aerator consist of?

Typically, a pond aeration system consists of:

Compressor; air nozzles with 4 mm connecting nipple; a multiplier with 4 mm fittings at the outlet – connects the nozzles to the compressor; silicone hoses with an inner diameter of 8/4 mm – connects the inlet of the breeder with the compressor/breeder with sprayers. Compressor models are equipped with multipliers with the number of output channels corresponding to the maximum productivity of the device.spring-type check valves – they are installed in front of the nozzles, their task is to prevent the freezing of aeration hoses in the winter.

The nuances of the design of the aerator depend on its type and principle of operation. For stocked ponds usually use vortex compressors.

 

Aeration efficiency

There are many ways to add oxygen to water. Most equipment manufacturers test their aeration devices for performance under standard conditions. 

One measure of aeration efficiency is the value of the “Standard Oxygen Transfer Rate”, the unit of measurement is kilograms (or pounds) of oxygen per hour. 

Another rating is “Standard Aeration Efficiency” or SEA. SEA is the value of the standard level of oxygen transfer divided by the power expended at the same time. 

The unit of measure for SEA is pounds of oxygen per horsepower per hour.

Pond Aeration

It is unrealistic to choose an aeration device according to the SEA level since it is impossible to take into account all the oxygen consumers in the pond besides fish. 

This indicator should be considered more in order to assess the effectiveness of the aeration device. 

To find out which device is most suitable for your pound, you should act not only according to the instructions but also experimentally.

Below is an analysis of aeration systems used in fish, parks, agricultural reservoirs of the world.

 

Aeration systems

Below are the most common aeration devices. For each device, the advantages (+) and disadvantages (-) are indicated

Fountains (sea level 1.5 – 2.5)

 

I like using small floating solar-powered fountains like the Solar Tech Fountain. They are easy to set up and work great.

These devices should be defined as devices that splash water into the air to create an aesthetically pleasing picture. 

There is a wide range of fountains on the market. Some are designed more for creating a water picture than for aeration, and some combine aesthetics with aeration. 

Such models are called aeration fountains.

+ May have a beautiful appearance and add beauty to the appearance of the pond

 

+ Some aeration effect is noted

 

+ Work well, it is enough in small, relatively small ponds

 

+ Very good for removing unwanted gases from water

 

– Usually, the height of their jets is not more than 3 m

 

– The aeration they produce is not very effective since part of the energy is used to form beautifully shaped jets

Aerators/circulators with drives from winds 

(sea level was not determined as there is no energy consumption) 

Wind turbines drive either a small compressor that directs air to the atomizer or a paddle of a certain type that is in the water and moves when there is wind.

+ No electricity required, so they can be used in remote areas

 

+ Nice appearance

 

– Do not work in the absence of wind

 

– Not portable, long installation time dictates the choice of installation location on the first try

 

– Do not work when they are needed the most – on calm, foggy summer days with cloudy skies

Floating aerators 

 

devices with a vertically installed rowing screw (sea level 2.6 – 3.2) 

 

Pond Aeration

These devices consist of a floating platform, an engine, and a propeller for spraying water on the surface. 

+ Ideal for small ponds

 

+ Pretty decent oxygen transfer rate

 

+ Have small size and weight

 

+ Not expensive

 

– Not effective enough when moving water at depths greater than 3m

 

Rowing wheel (sea level 2.6 – 3.2)

 

Pond Aeration

A rowing wheel is a shaft with blades that rotates with an engine or tractor power take-off. 

When the shaft rotates, the blades spray water. 

Rowing wheels have come a long way in the last 10 years and are used mainly in fisheries. 

Early designs are technically imperfect, which caused premature wear of the drive units. 

Newer projects have a better balancing and less wear.

+ May cause directional water flow during operation

 

+ The most efficient surface aeration apparatus

 

– Not effective when used in deep ponds

 

– Devices are usually large and difficult to carry

 

Horizontal aspirators (sea level 1.8 – 2.3)

 

Pond Aeration

 

These devices include an engine located above the water, a long shaft, a propeller, and a pipe through which air is sucked. The position of the pipe can be adjusted.

+ Direct flow to stagnant zones

+ The ability to change the installation angle of the pipe makes these devices effective when moving water in deep ponds

– Oxygen transfer is not as good as other devices

– There are frequent damage to the driveshaft

 

Pump-aerators (sea level 1.5 – 2.5)

Pond Aeration

 

These devices work like aspirators but do not suck in air. As in aspirators, the propeller is adjustable in direction. 

+ Excellent for causing water movement

+ Powerful enough to prevent freezing of water in winter and death of inhabitants from lack of oxygen

+ Can be installed in ponds with variable bottom topography and can mix deep waters

– Not as effective as other devices in terms of oxygen transfer

Water cascades (sea different level)

 

Pond Aeration

This method is similar to natural aeration. If water is supplied to the pond by a pump, it can be arranged so that the flow will boil, while the water is enriched with oxygen from contact with air. 

+ Natural aeration

+ The natural look of the water system

– Not as effective as mechanical devices

A purge of pure oxygen (sea different level)

Pure oxygen is usually added to fish ponds with a high concentration of oxygen consumers. Oxygen can be added from a locally installed generator or from cylinders.

+ If the oxygen concentration is close to saturation, this is the best method to increase the concentration

– An expensive and difficult to use method

– Oversaturation of water with released nitrogen can cause stress or death of the fish, from a condition similar to “decompression sickness”

 

Air sprays (sea level 1.0 – 4.0)

This method of aeration usually uses a compressor that pumps air in small volumes, but with high pressure. This allows you to spray it at depth. 

In deep ponds, the use of a compressor with a set of sprayers can be very effective for moving water and transferring oxygen.

+ The most effective deep pond aeration method

+ Lack of electrical appliances in water

+ Not much disturbance of surface water

– Hard to carry design

– Not effective enough for urgent enrichment of water with oxygen

– Not effective when applied in shallow ponds

 

Types of aerators

All aerators by type of installation are divided into two large groups:

Stationary: Devices installed in a specific reservoir. 

Work – permanent or in a certain mode.

Mobile: These are devices for temporary, seasonal use. 

They can be moved from place to place, installed in different reservoirs. 

Such devices are usually used in ponds of a small area, as well as in reservoirs that do not need constant oxygenation.

Can I assemble the aerator with my own hands?

If the owner of the pond has the skills to work with equipment and tools, you can save money by assembling the aerator with your own hands. 

Consider the processes of assembling devices of various types.

How to assemble an ejector aerator?

 

What you need to have:

drainage pump; sewer pipe 32 mm – 2 m and nozzle – 30-50 cm; angled tee at an angle of 45 degrees; corner at 45 degrees; double braided wire.

The pump is selected average power and cost, taking into account the area of ​​aeration. The cable is taken with a cross-section so that it can withstand the power of the consumed current, even during continuous operation.

Build process:

The pump is usually completed with an angular branch and the union under a hose. Seals are inserted into the sewer tee and connected to the fitting. 

You can use a silicone sealant to seal the joint. A pipe is attached to the second side of the tee.

An angle of 45 is placed in the upper branch, and a 2-meter pipe is attached to it.

It remains to connect the resulting design with an angular adapter of the pump.

Lead the cable. Cut the plug. The wires are twisted, wrapping with electrical tape. 

Then they are hidden in the coupling, pouring polymer.

If you do not cut the plug, you will have to use an extension cord. In this case, the socket with the plug is packed in polyethylene, and tightly wrapped with electrical tape.

The pump is placed at a depth of 70-100 cm. 

The intake pipe should be on the surface of the water. 

To do this, make a mast – from a steel pipe. 

They drive it into the ground. It is advisable to place the pump in a mesh container. The aerator is attached to the mast with wire. 

Now you can supply electricity.

A tee with a 90-degree angle cannot be used.

 If the angle is 45 degrees, then the air, being drawn in, moves and mixes with water. 

If the angle is 90 degrees, there is a risk of return air movement.

 

How to assemble a bottom aerator?

The assembly of such an aerator will cost inexpensively. For this design, you need a car compressor with a receiver. 

Also:

high pressure hose;clamp;tees;spray guns.

Sprayers can be made from half-liter polyethylene bottles. It is enough to make holes in them with an awl. To reduce the diameter of the emerging bubbles, the bottles are wrapped with foam.

Assembly line of a homemade bottom aerator:

The compressor is installed near the pond or in some nearby extension.

The compressor is connected to a central hose, which is pulled to a pond.

By means of tees make bends. The number of taps corresponds to the number of nozzles. Fixation reinforced brackets.

Diffusers attached to tees are placed at the bottom of the pond. 

To avoid lifting to the surface, they are crushed with stones or fixed with pins bent at the ends.

Bottom aerators can not work without a break. 

The devices also make noise, causing discomfort to others. Such devices are usually used for periodic saturation of water with oxygen.

How to assemble a Wind Aerator?

Wind turbines are especially good for wintertime. The assembly process is simple and does not require expensive parts. 

You will need:

metal sheet – a square with a side of 30 cm; steel rod 20 mm; bearings of the appropriate section; strips made of metal (thickness – 2 mm); capacity made of plastic; fan; fasteners.

Build Order:

8 squares are cut from a metal sheet.

Cubes are made of them. Cross members are placed inside the cubes, a hole is made in it and a bearing is placed. Bearing centers should be on one straight line.

The rod is inserted into the bearings.

The capacity of plastic is cut in half – these will be the blades for rotating the shaft. Using metal loops, the blades are mounted on the top of the rod. Support legs are welded to the structure. At the end of the shaft, a radiator propeller is fixed.

Now the structure can be lowered into the water.

Thanks to the wind, the blades are untwisted, transmitting rotation to the propeller located at the bottom of the shaft. 

The propeller, rotating, creates a vortex that prevents freezing of water in winter.

Aerators are an indispensable thing when growing fish in bodies of water with standing water. 

This device can be bought or made independently – the main thing is that the pump power is enough for aeration of a given area.

Aeration system selection criteria

The aerator is not cheap, but the cost of buying it is not comparable to the problems that arise in a body of water with standing water. 

Regardless of the purpose of the reservoir – decorative or domestic, aeration of the water is necessary. 

The industry produces aerators of various types – they differ not only in names but also in the principle of operation.

We tried to list all the devices used for aeration. 

Not every aeration method or device will work effectively in your pond, since each pond, lake, or body of water is unique in its characteristics. 

For garden ponds, it is customary to use household compressors with air sprayers, floating aerators, fountains-aerators, bottom aeration systems. 

Often aeration efficiency depends on the geographic region. 

Below are a few criteria to consider when choosing an aeration system.

Maintenance – How much time are you going to spend to properly maintain the device in order?

Safety – The electrical drive of many aeration devices is located in the water. Make sure all safety recommendations are followed.

Simplicity – Installation, and use of some devices can be very complex and time-consuming. Are you sure you can handle these problems?

Duration of the preparatory phase – For some equipment, this phase can be very long, which can cause problems when your fish and pond are in dire need of aeration.Costs – Some equipment can be quite expensive to purchase and require large operating costs.

When choosing a compressor, the dimensions of the reservoir are taken into account – each device is designed for a specific volume of water. 

 

What else you need to know about oxygen saturation of water:

The amount of oxygen in the water must meet the needs of the fish – its excess is as harmful as lack. Oxygen demand varies with the time of year. The type of aerator, its design, and the principle of operation are selected in accordance with the purpose of the pond.

Choosing an aerator, it is evaluated by such indicators:

compressor power; noisiness boundary temperatures for use of the device.

There is no exact formula for choosing a compressor. For each specific pond, the device is selected taking into account many factors:

stocking density; the presence of water plants; water temperature; biochemical composition of the soil; depth of the pond; the presence of shallow water; bottom configuration; the presence of shade above the water surface.

If the aerator is purchased for the first time, and it is not known what power will be optimal, start with a 40-60 Watt device. By installing an aerator, monitor the concentration of oxygen in the spray zone through special tests. With insufficient oxygen concentration, additional compressors are acquired – their quantity and power are determined empirically.

For aeration to be of high quality, it is necessary that the daily water flow of the system is four times the largest volume of the pond.

Under certain circumstances, it is necessary to increase the capacity of the aeration system by increasing the number of aerators in the pond if:

the reservoir is oversaturated with algae; organic matter gets together with stormwater; the reservoir has an irregular shape – this makes it difficult to mix the water.

On average, for every 10,000 square meters. m of water surface requires at least one aerator.