What is an aquaponics system? What is the difference between hydroponics and aquaponics?
Are you interested in learning more about aquaponics? Aquaponic systems are rapidly gaining popularity as a sustainable form of agriculture. Keep reading to learn what an aquaponics system is.
The word aquaponics is the result of combining the words aquaculture and hydroponics. Aquaculture is the farming of fish, while hydroponic systems are systems of growing plants without soil, i.e., in water.
By combining the two words, you can easily see what aquaponics is. Aquaponics is the growing of plants and fish farming in the same system.
Aquaponics aims to create a symbiotic relationship between the fish that are farmed and the crops that are grown. Aquaponics systems are more sustainable and require less input than other crop systems.
In a hydroponic system, plants are grown typically in a water and nutrient solution. In that regard, hydroponics and aquaponics aren’t different. The difference is in the way that the nutrients are delivered.
In an aquaponics system, the main supply of nutrients is from the fish that live in the system. The fecal material from the fish supply the ideal nutrients that the plants can use to grow. In some systems, the plants and fish are grown in the same tank. In other systems, the fish live in one tank and plants are grown in another tank. The water is flowed between the two tanks to supply the fish with fresh water and the plants with nutrient rich water.
Aquaponics vs. Hydroponics
Aquaponic systems are even more sustainable and profitable than hydroponic systems, which is saying a lot considering how productive hydroponic systems are.
Aquaponic systems allow growers to produce plants and clean, farm-raised protein. This provides growers more stability, especially if their typical crop experiences seasonal changes in demand. The demand for sustainable, farm-raised fish and seafood is growing and makes it easy for producers to break into the market and make a profit.
It’s also a great way to provide fresh vegetables and protein to your family if you have a small-scale operation.
4 Ways that Aquaponics is Better than Hydroponics
I mentioned that aquaponics is better than hydroponics, but I want to look at that a little bit deeper. Let’s look at why aquaponic systems are better than hydroponic systems.
Fish or seafood produce ammonia in their feces. If you’ve been gardening long, ammonia is a word that you’re probably familiar with. It’s a chemical that can be broken down into nitrogen. In an aquaponic system, bacteria break the ammonia down into usable nitrogen (fertilizer) for the plants.
2. Mimics Nature
Aquaponics systems are as close to nature as you can get. In an aquaponics system, you’re creating a symbiotic relationship between the fish and the plants, similar to what would occur in nature. You can see a similar relationship between lillypads and fish at a pond.
3. Reduced Waste
Fish farming alone can produce waste. By growing fish and plants in the same space, waste is reduced. There isn’t as much waste in a hydroponic system because they are highly efficient. However, you can often incorporate a fish tank into a greenhouse or hydroponics space and increase the productivity of the same space.
4. Improved Productivity
Adding fish to an existing hydroponic system is an excellent way to improve the productivity of a space. Many aquaponic systems can be fit into your existing greenhouse or hydroponic operation, increasing the amount of food and profit that you can produce in the same space.
How is aquaponics used in agriculture?
Hydroponic systems have been around for quite some time. In fact, the ancient gardens of Babylon used hydroponic gardening techniques, so it may seem that aquaponics is a relatively new idea.
Modern aquaponics systems started to appear in the 1970s when the term ‘aquaponics’ was coined. However, the practice of growing plants and fish in the same area is much older than that. The ancient Aztecs raised plants on rafts in small lakes that they created called ‘chinampas’.
Aquaponics today is used to increase the productivity of both fish farming and hydroponic systems. It’s a really effective way to raise sustainable seafood and fish along with producing eco-friendly plants.
Aquaponic systems have allowed fish farmers or vegetable growers to diversify their income streams and attract customers from different markets. This often helps growers that have specialty crops or produce crops or fish that have seasonal changes in demand. Being able to offer fish for sale at a time when you’re crops are in a dead period can help pay the bills.
For more information about what aquaponics is, check out this video:
Types of aquaponics systems
There are three types of systems that are commonly used in aquaponics: nutrient film technique (NFT), deepwater culture (DWC) and media beds.
Nutrient Film Technique (NFT)
A nutrient film technique system uses a series of pipes or gutters that are attached to the fish tank. The fish are in a separate tank since there would not be room for them in the NFT part of the system.
Nutrients and water are cycled throughout the entire system. The top of the gutters is closed off, so extra air filtration is necessary for plant and fish health.
This is the best system if you’re planning on growing small herbs, lettuce or leafy greens. NFT systems are shallow and cannot support the weight of larger crop plants like tomatoes and cucumbers.
Deepwater Culture (DWC)
This is probably the system that you picture when you think about growing fish and crops together. The fish and plants are located in the same tank. The tank is deep to give the fish ample room to move around.
Plants float on rafts on the surface of the tank. A downfall to this system is that you have to be careful of the fish species that you put in this tank. Plant roots hang down into the space where the fish are and can become food if you have plant eating fish in the tank.
This system is easy to create on a small scale and can be done with inexpensive equipment. There are also less fluctuations in water temperature and pH since you aren’t moving water from tank to tank.
Media beds are another viable option for the DIYer. In a media bed system, the fish tank is above the level of the beds that contain the plants. The plants are in a soilless media. The shallow trays are filled with clay pellets or other small, porous rocks.
Nutrient rich water from the fish tank is pumped into the media beds. This is often done with a gravity flow system. The water is then flushed from the media beds into a holding tank and pumped back into the fish tank.
Water can be a constant flow from the fish tank through the media beds or it can be a fill and dump system. This system is easy to set up on a small scale or large scale. A down fall can be the cost of the media and the frequency that pumps can get clogged with fish waste.
Animals Suited for Aquaponic Systems
Many aquaponic growers prefer to raise fish in their systems. There are many types of fish that do well in an aquaponic system. If you’re not interested in growing fish, they aren’t the only option for animals that can be raised in an aquaponic system.
Tilapia are probably the most commonly raised fish in aquaponic systems.
They have many qualities that make them hardy and easy to grow. They are easy breeders and will reproduce rapidly for you. Tilapia eat both plants and animals. They will keep your tanks free of algae since that’s a source of food for them.
Tilapia are fast growers and are a clean tasting fish that is popular with consumers. Tilapia do require warm water so they are best suited for aquaponic systems that are in a greenhouse.
Trout prefer to live in cold water and can thrive in aquaponic systems that are located outside of a greenhouse.
Trout don’t consume plants, making them good candidates for deepwater culture systems. Since they are carnivores, they will require food from you. Trout can be fed fish food, insects or aquatic invertebrates.
The large amounts of protein that these fish take in gives them rapid growth rates. They grow quickly and are very efficient at turning food into muscle mass.
Carp, at times throughout history, has been one of the most commonly raised fish.
Carp are known for being highly adaptable and hardy, which is part of why they make for such troublesome invasive species. They are omnivores, so they will eat both plants and animals. They can survive and thrive in many conditions, so they are well-suited to being raised in an outdoor aquaponics system where the weather fluctuates.
Carp are also very prolific and are excellent breeders. They will reproduce rapidly without any help from you, ensuring plenty of future generations.
Catfish are a popular fish consumed here in the U.S. Catfish have been farmed successfully for decades.
This fish is different in the fact that they don’t have messy scales. Cleaning catfish is easy; you simply skin them. They are omnivores and aren’t generally picky about what they eat. Their large appetites lead them to having fast growth rates.
If you’re looking for something to raise that isn’t a food product, you can tap into the pet market with koi fish. Koi are popular with people that have large aquariums or ponds that they want to raise fish in.
They are very hardy and can survive in many conditions. They’re also less likely to suffer from parasites. These relatives of carp are adaptable to almost any environment. Koi can have extremely long lifespans.
Be careful when putting koi into deep water culture systems. Koi are omnivores and will eat anything that they can, including plant roots.
Raising fish is a great way to produce healthy protein; but of the fish on this list, perch may be the healthiest. They are high in omega-3 fatty acids, which is an essential nutrient for brain health.
Perch are omnivores and will consume anything from crustaceans to plants, so they may not be a great fit for a deepwater culture system. Instead, opt for a media bed or a NFT system that is located inside of a greenhouse since perch prefer warm water.
Bass are large fish and require a big aquaponics system to live comfortably in. They are carnivorous, and will eat anything that they can get in their mouths. Bass have been known to not only consume insects, but snakes, smaller fish and even small birds and mammals.
The most profitable way to raise bass in an aquaponic system is done when the fish are harvested before they reach mature sizes. Large bass require a lot of feed to keep healthy, so harvesting at a slightly smaller size produces a more profitable fish that’s also better tasting.
Crustaceans can be raised with fish or alone. Many species of crustaceans can be raised successfully in aquaponics systems. Crawfish, mussels and freshwater prawns can all be raised in aquaponics systems.
They will generally help to keep the tank clean, since these species feed on the bottom, where most sediments settle in the tank.
Plants Suited for Aquaponic Systems
The plants that can be grown in an aquaponics system are the same plants that do well in a hydroponics system. You’ll be able to produce large amounts of leafy greens, tomatoes, cucumbers, eggplants, squash, herbs and even strawberries.
Keep in mind that you’ll have to be more careful about the crops that you grow, depending on the type of system that you have.
Deep water culture uses floating rafts that can become top heavy with large plants like tomatoes and cucumbers. Keep smaller crops on floating rafts in a DWC system.
Media beds are more stable and can be used to grow larger plants.
NFT systems don’t have the space that is needed by larger plants and are best suited to smaller plants also.
Bottom line, if you want to grow large plants like tomatoes, cucumbers and squash, set up a media bed system. If you are growing smaller plants like strawberries, leafy greens, lettuce or herbs, any of the aquaponics systems will work.
Is aquaponics for you?
Growing plants in a hydroponics system has a learning curve, but once you throw another factor (fish) into the mix, it becomes more complex. There is a definite learning curve when you start raising fish with plants.
A well-maintained aquaponics system has regulated temperatures, EC, pH, oxygen levels and nutrients. Once you’re system is running smoothly, it often creates an ideal symbiotic relationship that requires less input from you.
If you’re interested in keeping your profits more steady throughout the year, an aquaponics system may be a good option for you.
For more information about aquaponics, visit this page from USDA.