Koi's - Header image

Fish pond aerators - Types, Suppliers and Ideas

Fish Pond Aerators are a very important piece of equipment to add to your fish pond, they act as a live saver to your live stock in the warm weather and help to keep the pond balanced and prevent the water from becoming stagnant with low oxygen levels.

Water in any of the natural waterways has the ability to absorb enough oxygen to support its inhabitants but in the enclosed space of a pond this is a different matter, the fish pond keeper has to resort to artificial methods to keep the oxygen levels high enough, this problem is increased ten times in the warm summer months as higher water temperatures tend to expel oxygen and the supply is soon depleted. Sure signs of lox oxygen levels are fish gasping at the water surface, loss of appetite, infections catching hold of the fish quickly as their immune system weakens and slower growth rates if the oxygen levels are low all year round. Fish pond aerators are a good and reliable means of overcoming this problem.

Some pond keepers who are attempting for a natural balance will heavily stock the fish pond with plants hoping that this will keep the oxygen levels high through photosynthesis but sometimes this method can fail and all of the live stock are wiped out very quickly before the pond keeper can react quickly enough.

To understand how aerators can act efficiently it is wise to read up as to how the water in the fish pond absorbs the oxygen in the first place. Surface agitation is the most reliable method, as the surface moves it acts like sponge absorbing the oxygen and expelling toxic gases that are not required in the pond.

If the water surface is still, it will still absorb the oxygen but this does not get the chance to mix with the lower levels of water in the pond and as the top surface absorbs as much oxygen as it can, it will halt the gaseous exchange preventing any more oxygen entering the rest of the fish pond water. Even the slightest agitation will prevent this from happening and the whole of the water volume of the fish pond mixes keeping the oxygen levels even throughout.

Fish pond aerators not only agitate the surface but as the air breaks the surface it forms a small current moving the freshly oxygenated water away from the aerator thus moving the water about in the lower levels as well. It is a common misconception that it is the bubbles that the aerators create which add the oxygen to the water, this is true for a small percentage, the real work is done as the bubbles hit the water surface and agitate it.

Ever wondered why a lot of fish ponds have waterfalls? Yes, they are aesthetically pleasing to look at but they also act as an aerator as the water is pumped to the top of the waterfall and allowed to fall back into the fish pond breaking up the water surface.

There are many models of fish pond aerators to choose from so research the suppliers on the websites or visit fish pond suppliers to see which is the best for your fish pond. Ensure that you have a safe and adequate power supply near your fish pond as all models will require for a pump, this can either be a water pump or an air pump to power the aerator. The aerators powered by a water pump depend on creating a water flow around the fish pond whereas the air driven aerators will feed air into the aerator and disperse this through the water column from the bottom of the pond to create the water surface agitation plus creating water flow ( on a smaller scale to the filtration).

Fish pond aerators can be broken down into two basic groups, bottom mounted aerators and surface mounted aerators. The bottom mounted aerators are normally designed for the larger ponds with deeper water columns, shallower fish ponds are better suited with the surface mounted aerators whether it be a fountain or a waterfall as the shallower depths require less movement and the surface area still gets the same amount of agitation.

Fish pond aerators tend to be used more in the summer months as higher water temperatures result in lower oxygen levels, having said that running a fish pond aerator alongside a fish pond de-icer during the winter months will prevent a build up of toxic gases which could be detrimental to the health of your fish.

Bottom mounted fish pond aerators

Nowadays most of the bottom mounted fish pond aerators work by using a diffuser to disperse air through the water column. A few years ago some of the bottom mounted aerators had paddle wheel similar to the impeller that you can find in most aquarium filters, a disc has paddles or blades attached to it and as the disc rotates, the water is disperses to create the water flow. These seem to have lost a lot of their popularity recently, one reason for this could be that modern technology has developed cheaper units that are far more cost effective to run, some of the original paddle wheel assemblies were run by bulky motors with a high wattage or even diesel engines which in turn were very noisy and not cost effective to run for long periods of time.

Fish pond aerators that work with diffusers are very simple to set up and involve very few parts to connect. A powered air pump is connected to the diffuser by means of piping to carry the expelled air to the diffuser and this is weighted so that it will sit at the bottom of the pond, dependant on the size of the pond, more than one unit may be required but these can all be run from a single air pump with the correct rating by the attachment of a manifold that allows you to attach several airlines that can be shared over the total number of diffusers.

The diffusers themselves can be purchased in a variety of shapes and sizes, there is a disc version available that is as suggested a disc of plastic, ceramic or silicon that has fine holes in it to create a fine mist of air bubbles to escape into the water column. Creating a fine mist of bubbles means that less power is required by the air pump to create the mist plus there is a larger surface area on the bubbles making them a lot more efficient than larger bubbles. Due to the depth of the larger fish ponds it also ,means that the air bubbles have a longer contact time with the water as the rise from the depths to the water surface.

Surface fish pond aerators

Surface fish pond aerators come in a great variety, for the purpose of this article, I have included waterfalls and fixed fountains as they all work on the same principle as floating surface aerators. Waterfalls are often the most common aerator added to any fish pond, most of the time these are added for their aesthetic look to the fish pond with the pond keepers not actually realising how beneficial they actually are. Normally they are sited at one end of the pond and the water is pumped to the top of the waterfall where a small header pool is allowed to fill with water before being allowed to trickle back down the waterfall pathway back into the pond, agitating the water surface as it enters.

Fountains also have water pumped to the head of the fountain before being released back into the fish pond. There are several designs of fountain heads which can create a variety of water patterns that make for a grand display above the water surface. These can be fixed on a permanent basis to a solid stand that is built under the water surface and the water pump is placed below the fountain head, both these and waterfalls require a power supply to feed the pumps so always bear this in mind.

This type of fish pond aerator are ideal for the shallower ponds but they can also be used in deeper ponds if you wish, with shallower fish ponds they do become their most efficient as the water not only agitates the water surface but the pump feeds the fountains and waterfalls from the lower levels keeping all water in the fish pond oxygenated. They are not so efficient with deeper fish ponds as the higher the water has to be pumped to reach the top of the waterfall or fountain, the larger the wattage of water pump has to be to cope with the extra pressure, this would mean higher running costs overall.

For those of you that wish to reduce the running costs even further there are now available aerators that are purely solar powered, these have a couple of advantages over the other units, they do not need to be fixed in a permanent position, they can float around the fish pond with the power of the slightest wind movement, they are also in favour with our ever conscious people concerned about the “green effect” on the planet, solar powered devices are not a drain on the power supplies so do not add an extra load to the green house effect.

Suppliers of fish pond aerators ( all prices correct at 2011)

As stated above, fish pond aerators come in many shapes and sizes, this also is reflected in a wide price range. Expect to pay more for aerators that have more power for the deeper fish ponds although having said that some of the more ornate fountain systems can still fetch a good price but if the models are from reliable manufacturers they should provide many years of trouble free aeration.

Below are a few suppliers to help you on with your search and approximate prices at the time this article has been written:-

UK Suppliers

This company has a variety of bottom mounted aerators that start in price from £65.00 right up to £225. The Oxy Tex 400 CWS model has artificial foliage at the top of the diffuser to house beneficial bacteria and according to the model description can improve the filtration of the fish pond by 10%. This is the smallest of the range and starts at £65.00 but it does not come with an air pump so bear this in mind when costing up.

This company stocks the Oase range of aerators, they have the bottom mounted aerators as well as surface aerators and are a well established company that can supply all of your equipment needs. One of their cheaper models is the Gardena Aquamotion Pond Aerator that comes complete with the diffuser air pump and airline all for the price of £40.

US Suppliers

Yet another company that can supply all of your fish pond needs from one visit. For a powerful pump check out the L D Aerator that can work efficiently in fish ponds up to 8 feet in depth. These do not come cheap, they are priced at $480 but for the larger fish ponds they have the power that is required to aerate the water efficiently.

Yet another US company that can supply all of your needs from the one website. They have a vast range of pond aerators and fountain kits for you to choose from, one example being the Toba fountain which is available with a variety of heads to give you the choice of which cascading water pattern you prefer. These start at prices of $860 but they are self contained units and can even be supplied with lighting to make the fountain even more dramatic.

The links above are just a few examples of suppliers, there are many more to browse around, most of the local garden centres are now equipped to provide pond equipment so always give them a good look around and have a day out while shopping!