Aqua FAQs

Aeration Systems

Will aeration improve water quality and clarity?

A properly-installed, personally-tailored aeration system has the potential to turn your mucky, green, pungent-smelling pond into a blue, crystal clear body of water with a vibrant aquatic ecosystem. Aeration increases the natural ‘turnover’ cycle frequency from a few times a year to several times a day. It is the process of deep water mixing with the surface water through the interaction of temperatures. The surface water is well-oxygenated whilst the deep water is not, so circulating the two means that the deeper waters will increase in oxygen levels, lower nutrient levels and above all, continue to sustain life.


Is it hard to change the air filter on my aeration system?

No, the process is quite simple and there will be information provided to you on purchase of your aeration equipment. Of course, feel free to quickly contact a Solair Group team member If you would like to ask us directly. The air filters should be replaced when they become soiled and be sure to check the air intake vents to make sure there is no debris that could restrict flow.


What is the difference between surface and submersed aeration?

Surface and submersed aeration are two methods that both aim to increase the amount of dissolved oxygen in the water, but go about it in almost opposite ways. Surface aeration involves an intake of water close to the surface being flung into the air where it is able to collect oxygen from the atmosphere. This can be a great technique in an emergency as it quickly increases the amount of dissolved oxygen in a concentrated area for fish to congregate.

On the other hand, a submerged aerator sits below the surface of the water and discharges air bubbles pumped from the surface that release the oxygen they contain as they rise. This technique, however, we do not advise utilising in an emergency. During the initial stages of operation for a newly installed submerged aeration system, there may be sludge or other organic matter pushed up to the top which can have a negative effect on the water quality and possibly cause a bad smell. The sludge may increase the demand for oxygen and the presence of nutrients such as nitrogen and phosphorus, but as long as the system continues to run, it will counter these effects until the water quality has improved overall.


Will aeration control algae and weed problems?

Algae? Absolutely! Weeds? Not so much. A majority of water catchments can really benefit from the installation of an aeration system due to its ability to stimulate water circulation. This frequent circulation will increase the level of biologicals in the water, which counteracts the growth of algae directly as algae gains its nutrients from the water itself. It will also provide enough oxygen to assist bacteria and enzymes in processing the dead organic matter produced from decaying sludge, meaning it is a great long-term solution too. However, aeration has no effect on rooted plants as they gain their nutrients from root systems in the soil of the lake bottom.


How does aeration put oxygen into the water? At what rate?

Aeration increases the dissolved oxygen levels of the water by simply supplying air pumped from above group to a diffuser settled at the bottom, which will break up the air into tiny bubbles that rise to the surface. Lake aeration devices can vary in the quantity supplied over a period of time from about 0.6 to 6 kilograms per kilowatt per hour. Devices such as fountains are more about the aesthetic affect and therefore have a lower rate of oxygen transfer. Then for something like a synergistic airlift, it’s quite the opposite. Very little energy is wasted on anything else but pumping oxygen, meaning they are able to circulate very large amounts of water.


How long will it take for aeration to improve a lake?

Various changes will be underway as soon as the system is switched on. For you to actually see visible improvements from the surface of the water, it should take at least 5-6 weeks or possibly up to a year depending on the dimensions of the water body. From then, assuming no additional nutrients are introduced, water quality will continue to improve.


How loud is a Solair Group System?

Our housing cabinets have been designed to reduce the overall noise level of the system when in use. As a result, at 3 meters away noise levels will be below 55 decibels and at 15 meters the system will not be heard.


Does the aeration system have to run continuously?

Yes. The aeration systems we manufacture are designed to run indefinitely, be it from mains power or a solar system. Having it switched on 24/7 will ensure progress is continuous and changes made are not able to be reverted. However, in the colder parts of the year, oxygen consumption may be low enough that the systems do not necessarily need to be operating.


Can the Solair Group system be used during the winter?

The system can indeed be used during the winter, but in some cases, it might not be necessary. It may be cold enough that the lake is actually able to sustain itself for a period of time. If the water gets cold and the dissolved oxygen at the bottom of the water body remains above 5 ppm, the aid of an aeration system is not needed. If the lake ices over briefly and there is no recorded history of winter fishkills, then it is safe to leave the system switched off. However, if there is a history of fishkills, the system can be operated to ensure no loss of life. Remember, having the aeration system switched on while a layer of ice is present over the surface of the water will most likely result in a hole opening up around a diffuser boil. This can be very dangerous for people and animals in the area, so take safety precautions. Local regulations may also require you to put up a warning sign.


What is the maintenance for the Solair Group system?

The components that will require maintenance include the air filter, the carbon vanes and the diffusers. The air filter should be checked for abnormalities and cleaned every 3 months, the carbon vanes will need replacing every 9 to 12 months and the diffusers should be cleaned about every 3 years or as necessary. Also, in some cases the compressor unit itself should be replaced or just the motor bearings.

How much will it cost in electricity per month?

Assuming a rate of 10 cents per kilowatt hour (which can be subject to change), one horsepower, running continuously for 30 days will cost $72. Actual power consumption may affect cost as well.


Should bottom aeration or surface aeration be used in a lake where trout are raised

It depends on the surface temperature of your lake. Generally, trout live in water no warmer than 20°C, so if your surface temperature does not rise above this throughout all parts of the year, then bottom aeration will do the trick. However, should you find your lakes surface temperature rising above 20°C during hotter seasons, neither will be sufficient. The bottom layer of the lake may be deprived of oxygen, unable to support the trout. However, Solair Group can design for you a hypolimnetic aeration or pure oxygen system adding to the bottom strata only.


How long does it take to install the system?

Generally, our Solair Group installation team can get it all done in 1 to 3 hours. Difficulties can arise depending on the distance from mains power to the water itself. However, should it be too far away, we can place the air compressor near the mains power and run the airline to the catchment. Extra time will also be required should you choose to trench the airlines into the ground or pour a concrete pad for the compressor cabinet to sit on.


What is the difference between a 4- and a 6- diffuser manifold?

The 4-diffuser manifold is generally designed for shallow water bodies where shallow water short-circuiting could be an issue, while the 6-diffuser manifold is much more effective in applications with deeper water.


Will the diffuser manifolds stir up mud on the bottom of the pond?

They will not, but loose sediment can rise to the top during initial installation simply as a result of the diffuser placement disturbing and breaking up sediment.


How many diffusers should be used?

It depends on the dimensions of your water body. If you get in contact with one of Solair Groups hydrology engineers, we can provide a free consultation or even provide a layout sketch. Sending us your details, either ton the ‘Selecting your Aeration System’ page or via email, will help us determine what is best for you.


How far apart should the diffusers be placed?

For ideal distribution, the diffusers should be placed at equal distances from each other and the shore. However, significant contours can affect the placement, so in that case, we recommend you get in contact with us. Bathymetric Mapping may be required to draw up a suitable aeration schematic.


If I live on a large lake, can I just aerate my backyard portion?

Aerating only a smaller section of a large lake will not provide any significant overall benefits. If a diffuser was placed above the thermocline, water would circulate, and fish would be attracted to the diffuser. If a diffuser was placed below the thermocline, the worst quality water would be brought up and displayed on the surface of your water body. For effective results, we recommend aeration is designed for the entire lake or a hypolimnetically isolated portion of the lake.


Do I need an aeration system for my pond or lake?

A majority a water catchments like lakes and ponds can really profit from the installation of an aeration system. From our experience, here at Solair Group, aeration is vital to improve and maintain the overall water quality and help sustain all kinds of aquatic life for years to come. It can increase the amount of dissolved oxygen in the water and can help fight back against phenomena such as stratification. To read more about the benefits of aeration, click here.


When I install an aeration system on a lake or pond, can I expect any negative impact on water quality initially from gunk being mixed up at the bottom?

During the initial stages of operation for a newly installed aeration system, there may be sludge or other organic matter pushed up to the top which can indeed have a negative effect of the water quality and possibly cause a bad smell.

The sludge may increase the demand for oxygen and the presence of nutrients such as nitrogen and phosphorus, but as long as the system continues to run, it will counter these effects till the water quality has improved overall.


How long does a solar aerator take to clear a pond?

There will be changes as soon as the system is switched on regardless of whether it is a solar system or one powered by mains. For you to actually see visible improvements from the surface of the water, it should take around 5-6 weeks.


What is a pond bubbler?

A pond bubbler is simply another name for an aeration system. A pond bubbler releases air bubbles through diffusers at the bottom of the lake from an air compressor to increase the frequency of turnover from a few times a year to several times a day.


Is my waterfall enough aeration for my pond?

Waterfalls may be helpful but they are usually not enough to rely on to improve and sustain the water quality. Even large water falls may not have enough force to be able to distribute oxygen. Also, if you have a waterfall in your pond or lake, keep you pump intake away from the waterfall itself or else there might not be enough circulation.


I have seen aeration systems used in a pond or lake in winter, but there is a hole in the ice. Isn’t that dangerous?

This can definitely be dangerous to people or animals in the area. While it is a good sign that the aeration system is working to improve water quality and keep aquatic life alive, you should never attempt to walk on the ice. You may be required by local regulations to put up a warning sign.


Activated Sludge

While the micro-organisms are in use, is it safe for animals to enter the water?

It most certainly is! The products we use are non-toxic and made from all natural ingredients. They work to provide a long-term solution that is natural and completely safe.

Feel free to let the kids or the dog have a swim!


How long does it take activated sludge to work?

The micro-organisms used in our activated sludge are great for balancing the aquatic ecosystem and improving the overall quality of the water. As soon as they are dropped in the water, they will begin to ‘eat away’ at your unwanted nutrients. To start seeing significant improvements, it really depends on the volume of excess nutrients you started with. If you have an abundance it will take longer than if you didn’t. Usually, significant changes can be observed after 4-6 weeks.


Do you sell wholesale for dealers?

We do indeed! Feel free to contact us should you be interested becoming a Solair Group product dealer.


Fish and Aquatic Life

Why are my fish gaping at the surface?

If you see this occurring in your pond or lake, you should act as soon as possible. Fish gaping at the surface means oxygen levels are low so they gape at the surface where oxygen levels are highest. Supplemental aeration is required to quickly get those oxygen levels back up.


Pond and Lake

Why is my pond water green?

This is a sign of microscopic algae in the water, possibly caused by large algae blooms. While it looks gross, it can also be lethal for aquatic life and hence should be dealt with appropriately.


What is pond scum?

Pond scum is another word for algae at the surface of the water or the organic sludge layer at the bottom. Neither are good signs for the water quality or overall health of the pond or lake.



Why does my pond/lake stink?

This could be for number of reasons, but the most common causes for pungent odours are anaerobic bacteria and algae blooms.

In untreated water bodies, anoxic conditions can build up at the bottom, meaning there is little to no oxygen present. In these conditions, anaerobic bacteria flourish and emit a rotten egg smell in the form of hydrogen sulphide. This can be made even more unpleasant during windy weather or even during the initial operation of a newly installed aeration system as that gas will be pushed to the surface.

During large algae blooms, planktonic algae can build up and can emit different compounds with bas smells.


Does the warmer weather effect my pond or lake?

During this time, your pond or lake might be at risk if you are not equipped with the appropriate countermeasures. Firstly, weeds are going to love the extra warmth and sunlight and will use it to help them grow. However, they will also use large amounts of oxygen to grow and decompose, meaning other plants and aquatic life are at risk of suffocation.

Secondly, the added heat could lead to a phenomenon known as stratification. The water body will separate into two layers due to the differences in density with temperature. As this goes on, this will magnify to the point where dissolved oxygen in the upper layer has dramatically decreased and sludge has built up at the bottom. When it comes to the time of year when these two layers mix during a process called ‘turnover’, dissolved oxygen levels plummet which can lead to the death of aquatic life.

Aeration is a great solution to this problem as it increases the natural frequency of turnover to a few times a year to several times a day, making stratification a think of the past.


Why is my pond cloudy-looking?

Cloudiness, or ‘turbidity’, is the result of suspended particles in the water. These suspended particles can be dissolved organic material, which is brown in colour, or suspended clay particles, which has a tan appearance.


What are the weeds growing in my pond?

The weeds growing are known as aquatic vascular plants and are a natural part of aquatic ecosystems. Though, much like the weeds in your driveway, they can spread if not properly monitored. If you pond or lake has an abundance of excess nutrients, it may be classified as a ‘eutrophic’ lake. Under these conditions, weeds have the potential to overgrow the entire pond.


Why can’t my fish live through winter?

This is caused by an unfortunate phenomenon known as ‘turnover’, which can lower the oxygen levels for the fish in your water body during the stratification cycle.


What is a “de-icer” and why would I need one?

A de-icer is used to maintain a minimal amount of ice on you water body. This can be beneficial for your fish as the process improves the water quality to ensure they don’t die and can even attract aquatic bird life. On top of that, it can prevent damage to boats or docks, which is great news for you!

Is there anything I can do in the cold seasons so my pond is in better shape, come spring?

The top two methods we recommend are aeration and activated sludge. Both are great processes for improving your overall water quality and making sure it remains sustainable for aquatic life for years to come. They can be applied any time during the year and require minimal maintenance/supervision, which means you’ll have more free time when spring comes around!


What is pond sludge?

At the bottom of your lake or pond, organic material can build up into a foul-smelling layer. This is known as sludge. It can be made up of leaves, decomposed algae and fish and wildlife waste. This layer at the bottom can pose problems for your water body as it increases the demand for oxygen. If left untreated the problem can escalate to the anoxic conditions, meaning little to no oxygen at all.