Aquaponics has gained traction over the past ten years as more and more people are seeking sustainable ways to organically grow plants.
Aquaponics is the combination of aquaculture (growing fishes in tanks) and hydroponics (growing plants in nutrient-rich water), where microbes convert the waste from fishes to nutrients or fertilizer, for plants to grow, in a closed, recirculating system.
The subject may seem taboo for some people, seeing plants grow without soil. But in essence, it’s just science and nature at work. What is even more appealing is that crops grown in aquaponic systems are totally organic.
Crops that I have found to thrive in aquaponic systems includes:-lettuces, cucumbers, tomatoes, Pak Choi, and seasonings.
What does Aquaponics Mean?
The word Aquaponic is essentially a combination of two words
Aqua – which is derived from Latin which stands for water, liquid, or a solution, or something that takes place in water.
Ponics – The ponics part of the word also has a Greek root, ponein, “to labor or toil.”
How does Aquaponics Work?
Have you ever wondered why fish lovers and fish enthusiasts alike, have plants in their aquarium? The plants not only add a pretty look to the aquarium. It has a very important purpose.
Fishes produce waste when they eat food and carry about their normal daily cycle. This waste contains ammonia, a very toxic chemical if allowed to build up in the aquarium, which can eventually kill the fish.
Adding plants to the system reduces the ammonia produced from the fish poop and creates a very comfortable environment for the fish to thrive.
This is Aquaponics at work!
In aquaponic systems, there are three main components – Fish, Plants, and Microbes.
The fish provides nutrients in the form of their waste. You may be wondering. How on earth poop can be good? Actually, it can!
The waste from the fishes contains nitrogen in the form of ammonia (NH3). Plants love nitrogen and they use it to grow and produce green leafy branches.
We know that Ammonia is toxic to the fishes and luckily in aquaponics, there is a friendly bacteria that changes the ammonia into a nutrient that plants love.
There are two very important types of bacteria responsible for the conversion which takes place in two steps.
Nitrifying bacteria converts the ammonia firstly into nitrites, which is an intermediate step, then to nitrates which plants use as nutrients to grow.
Nitrifying bacteria, Nitrosomonas and Nitrobacter are important microorganisms that help keep an aquaponics system in balance. Nitrosomonas converts ammonia to nitrites and Nitrobacter sp. converts nitrites to nitrates.
This forms a continuous closed-loop system where plants and fishes live and thrive in symbiosis. It’s basically an ecosystem where plants fishes and bacteria live in harmony.
What is the purpose of Aquaponics?
The purpose of aquaponics is to provide a food source in a sustainable manner.
The American Public Health Association (APHA) defines a sustainable food system as –
One that provides healthy food to meet current food needs while maintaining healthy ecosystems that can also provide food for generations to come with minimal negative impact to the environment.
An aquaponic system does just this, by raising fish and growing crops while minimizing the impact on the environment. The water is recirculated and continually reused while there is no need to add fertilizer for the crops to grow.
Types of Aquaponics systems
Recirculating aquaculture systems (RAS) are used in home aquaria and for fish production where water exchange is limited and the use of biofiltration is required to reduce ammonia toxicity. [Source]
Recirculating aquaculture systems (RAS) are self-contained growing environments for producing aquatic organisms.
There are three types of aquaponics systems all of which follow the RAS architecture.
- Deep Water Culture (DWC)
- Nutrient Film Technique (NFT)
- Media bed or Grow beds
1. Deep Water Culture (DWC)
In this method, the plant roots are suspended in a solution of nutrient-rich water. This can be done by placing plants in rafts that float on the surface of the water.
2. Nutrient Film Technique (NFT)
This is where the roots of the plants are just touching the surface of the running water. It may not seem like much but this method has many benefits compared to other techniques. (shown in the Pictures above)
Lettuces, Bok-Choy, broccoli, Cauliflower, and certain herbs are best suited for an NFT aquaponics system. This is because these plants are lightweight, leafy green plants with short root systems which thrive in nitrogen-rich nutrients.
See our detailed post on the best plants to grow in an NFT system.
3. Media bed or Grow beds
Grow beds contain growing mediums such as gravel, hydroton balls, or other substrates to which the plant roots can hold on to.
The growing medium simply provides support and not nutrients for the plants like what normal soil would do.
The Main Components of an Aquapoinc System
The components that make up an aquaponics system are.
- The Fish tank
- Mechanical filter
- Bio Filter
- Growing medium
- Sump
- Fishes
For Example one of the most popular types of aquaponic systems is NFT, which stands for Nutrient Film Technique.
1. Fish Tank
This is where the fishes and aeration mechanisms are housed. Fish tanks can vary in size depending on the number of plants in the aquaponics system which determines the number of fishes required to produce the required nutrients.
Sizing the tank for the number of fishes required is an important factor in aquaponics to get optimal output from the system.
Aeration is also important as it provides oxygen for both the fish and the plants and is also highly dependent on the volume of water in the tank.
There are many different types of fish and aquatic animals which can be used in aquaponics, all of which are housed within the tanks.
Depending on the location of the aquaponic system you may need to cover the tank to ensure that the sunlight does not cause unwanted algae blooms as well as fluctuations in water temperature which can deplete oxygen supply and kill fish.
See the importance of covering the fish tank here as well as what can go wrong in aquaponics.
2. Mechanical filter
This is the first stage of filtration in an aquaponics system and is where most of the heavy poop matter ends up. This filter makes it easy to remove heavy matter through drains and cleaning mechanisms.
If the waste is allowed to build in a system, the ammonia concentration will also build. The resident-friendly bacteria may not be able to handle the overload and as a result, the fish would die.
There are many types of mechanical filters, all of which perform the same important function.
Our post on mechanical filters will give you a better understanding of how it works as well as how to set it up for success.
3. Bio Filter
The biofilter is the secondary part of the filtration system and is where the clean-up action takes place where the bacteria convert the ammonia into useful nitrates for the plants.
The biofilter is a component of an aquaponic system that contains bio media which increases the surface area for beneficial bacteria to thrive. The bacteria attached to the bio media convert ammonia into nitrates or nutrients for plants to grow.
The biofilter has a big part to play in the design, layout, and operation of a successful aquaponic system and is usually placed after the mechanical filter.
Biofilters are essentially made by filling a container with bio media, which are designed to increase the surface area for the bacteria to live.
Biofilters are simple and easy to construct helps perform the most important task in an aquaponic system.
Biofilters can be either static or moving:
Static
A static biofilter is where the filter medium remains in place and does move either by the churning action of an air stone or the water.
The bacteria in this system will attach themselves to the medium and will constantly build over time.
One downside to the static type biofilter is that the bacterial tends to clump up and fall to the bottom and can be messy to clean in the long run.
Get a better understanding of how to set up a biofilter here.
Moving Biofilter or Moving Bed Bio Reactor (MBBR)
An aquaponic MBBR reduces the ammonia and nitrite concentrations in aquaponics by allowing nitrifying bacteria to colonize within the media which are constantly being moved around by air bubbles produced by an air pump.
The types of media used in a moving bed bioreactor (MBBR) are usually the ones that are small with a large surface area that can be churned around by the currents caused by the bubbles from the air pump.
K1 and K3 media are one of the main types used which features a lightweight with large surface area design.
The K1 media has a larger surface area than the K3 Media and is often used in DIY MBBR applications and aquaponics. K1 media is fluidized easily meaning that it can be churned around with little air bubbles.
You can find cost-effective biofilter media on amazon by clicking here.
See our detailed post on Moving bed bio filter here.
4. Growing medium
The growing medium is where the plants are grown. The growing medium can be made from gravel, hydroton balls, PVC pipes, or floating rafts.
The primary purpose is to hold the plants in place for them to absorb the nutrients from the water.
5. The Sump
The sump is a small part of the system. It usually sits at the lowest point in an aquaponic system, this is where all the water ends up after passing through the plants.
The sump houses the water pump which circulates the nutrient-rich water throughout the system.
This may seem a simple task but if the pump fails, the entire system will also fail. For this reason, many aquaponic farmers install critical backup systems to prevent things from going belly up. Literally!
In addition to the sump, an overflow tank can be placed before the sump to catch or retain vital nutrient-rich water which may overflow in the event of a pump or power failure.
See the importance of having an overflow tank and how it actually works in saving the aquaponic water whenever the water pump shuts down.
6. Fishes
Almost any aquatic animal can be used for aquaponics. However, the most popular is fish.
List of fishes used in aquaponics:
- Tilapia.
- Blue gill/brim/sunfish/crappie.
- Catfish.
- Carp.
- Koi.
- Fancy goldfish.
- Pacu.
- Ornamental fish such as angelfish, guppies, tetras, swordfish, mollies.
The most popular fish used in aquaponics is Tilapia. Tilapia are resilient and can cope with pH, nutrients, and temperature swings which makes them ideal in keeping an aquaponic system functional.
Other Important Aquaponic Periferal Equipment
Water Pump
The best water pump for aquaponics can be chosen based on the flow rate (GPH), head height, power consumption, and pump placement. These factors determine how well the pump performs while circulating water throughout the system.
The water pump is like the heart of the entire aquaponic system.
It transports both Nutrients and Oxygen to where it is needed in the system.
Aquaponic systems are driven by the flow of water through the system. The flow of this water is measured in gallons per hour or GPH.
GPH is the unit you will see when searching for pumps and also the part of the determining factor in choosing the right pump for your system.
A general rule of thumb is that the pump should be able to recirculate all the water in the system within two hours. Meaning, that if you have a 250 gallons IBC tank, the pump should have a flow rate of at least 125 GPH.
See how to choose the best water pump for your aquaponic system.
Air Pump
Choosing an air pump for an aquaponics system depends on factors such as fish stock, plant density, water volume, turbulence, and depth of the water in the fish tank.
These factors determine the quantity of dissolved oxygen needed and the size of the air pump required to supply the oxygen demand for the system.
An air pump supplies oxygen to water by pumping air from the atmosphere into the water in the form of bubbles. The air pump works well with air stones which help to further break up the bubbles into smaller ones for maximum oxygen to be dissolved into the water.
Fishes and plants use this vital oxygen to carry out their daily functions.
See our detailed post on what you need to know when choosing the best air pump for your system.
Air Stones
Having an air pump is not enough. You need to break up the air into smaller bubbles so that the oxygen from the atmosphere can be efficiently delivered to the water where it is needed.
By increasing the surface area of the air (creating small minute bubbles) a greater amount of oxygen from the air gets dissolved into the water.
Without the air stone, the oxygen content in the water will quickly be depleted even if you have an air pump running with only a tube inserted into the water.
Venturi Aerator
Stemming from water aeration, another way you can effectively increase the oxygen content in the water is by the use of a venturi.
A venturi is a pipe with a restriction that draws air into the water stream which is then expelled into the fish tank.
As the water is drawn into the water stream it creates minute bubbles similar to an air stone. This helps in creating a larger surface area for the oxygen to be dissolved into the water.
A venturi is connected to the discharge end of the water pump, where the water pressure is the highest.
See our detailed post on how a venturi works and how you can make your very own from simple materials.
There are also cheap ready-made options from amazon that are also really effective. You can find them by clicking here.
BioFilter Medium
The biofilter media is where the majority of the nitrifying bacteria in the aquaponic system live.
An effective media is made such that it creates a large open surface area for the bacteria to call home while at the same time allowing oxygenated water to flow through.
There are many options when it comes to biofilter medium. A very cost-effective media that I use on my system is old fish nets which can be found close to any fishery.
Additionally, bio balls and K2, K3 media are also just as effective in housing beneficial bacteria and they do last a really long time.
You can see our picks on amazon for bio balls and K2 media.
Water Quality Test Kit
Water quality is also very important in keeping both healthy plants and fish. Plants grown in an aquaponic system depend on a steady supply of nutrient-rich water.
The nutrient availability to the plants is, however, dependent on the pH of the water. Plants thrive well in an environment where the pH is between 6.5 to 7.0.
Both nutrient levels and pH can fluctuate at times which will have a direct impact on the health of the system.
Having a water quality test kit will allow you to monitor and keep a close eye on nutrient levels, pH, and ammonia levels so both the plants and fishes can thrive.
There are many good options for testing water quality but we have found that the API water test kit from amazon is simple and gets the job done. You can find it by clicking here.
Net Cups
These are the resting grounds for the plants to grow. Net cups are simple cups that are perforated with large enough holes for the plant to grow its roots without restriction.
The cups help hold the plants in places within a plant rail or a Deepwater culture system.
Plant Rails
The plant rail is what holds both the plant and net cup in place in an NFT aquaponic system.
A rail is basically a straight pipe through which the water flows and comes into contact with the plant roots.
The pipes can be round or square and are often very rigid and durable.
I built my system with these affordable equipment from amazon.
Click on the links to view on amazon
Best Water Pump | Best Air Pump |  Best Air Stones |
Plant Net cups | Bio Filter Medium | Water Test Kit |
How easy it is to start an Aquaponics System?
Aquaponics systems are simple to set up. On a difficulty scale from 1 to 10, I would say a small DIY backyard setup is at 5.
With just a tank and a few fish, anyone can start an aquaponic system. Even if you have fish in an aquarium, you can start from there.
If you are looking to provide your family with a sustainable source of food, this is for you. This type of system is also suited for those who are interested in off-the-grid type projects.
Once you start to see the benefits and the yield of crops your produce within the short space of time you may want to scale your project so it can even bring in some income.
Examples of DIY Aquaponic Systems:
IBC Aquaponics.
An Aquaponic system is easy to set up by using an IBC tote. For many aquaponic beginners, using IBC totes is a cost-effective way to start a new aquaponic hobby.
An entire aquaponic system can be made from a single IBC tote which when installed correctly can have benefits such as a very small footprint and is easy to manage.
Barrel Aquaponics or Barrelponics
A barrel aquaponics system uses a 55-gallon drum which is cut such that one half is made into the fish tank and the other half is used for growing plants in grow media. Water circulation and aeration is provided by water and air pumps.
Turning a 55 gallon, blue barrel into an aquaponics system is a simple process and can be done by the chop and flip method, similar to an IBC aquaponic build.
It can be done in a small backyard, porch, or even in an indoor setting with the necessary grow lights.
In this type of system, there is no need for a biofilter since the grow beds create enough surface area for bacteria to live.
Is there Money in Aquaponics?
Yes, there is! When you get your system up and running, you would get a feel for the cost it requires to produce the crop.
This will allow you to scale your system to not only provide for your family but also to make a profit from the sales.
Remember you have both fishes and plants that run your system. Apart from the plants that grow and produce food, you have the fishes which in turn reproduce and make more fish. So it’s a win-win.
See our post on how much it cost to start your aquaponic system.
The Pros and Cons of Aquaponics
| PROS | CONS |
|---|---|
| Less Water | Unsuspected Failure |
| Less Space | Electricity consumption |
| No Weeds | Not many crops Available |
| Fast Growth | High initial cost |
| Continuous Production | |
| Environmentally Friendly | |
| Easy to Maintain | |
| Good Source of Income | |
| Affordable |
Aquaponics Compared to Hydroponics
The difference between hydroponics and aquaponics is that aquaponics uses fish to provide nutrients, and hydroponics uses formulated solutions.
The solutions which are used to provide the plant with nutrients in hydroponics systems must be always monitored and kept constant. Each plant requires its own blend of formulas to get optimal growth.
Aquaponics is much easier to control and is suitable to cultivate multiple crops in the same circulating solution. The added benefit of aquaponics is that you also have fish to provide that much-needed protein in your diet.
See how we made an automatic fish feeder for our system automation.
