Aquaponics, which combines aquaculture and hydroponics, is one of the leading urban farming techniques. Aquaculture involves raising aquatic animals such as fish in a controlled artificial environment.
Fish are raised in plastic tanks, either circular or rectangular in shape. These tanks provide the fish with pellet food and maintain constant water parameters such as oxygen levels, solid concentration, and carbon dioxide levels.
Hydroponics is the cultivation of plants using a nutritious medium without soil, and all hydroponic systems provide plants with nutrition through their roots in an aquaponics system.
How aquaponics operates
The fish in the tank eat food and release nitrogenous waste into the water. The wastewater, along with any leftover food, is sent to the biofilter unit where bacteria and fungi break it down into simpler nutrients.
After being filtered, the nutritious water is pumped into the hydroponic unit where the plants absorb the nutrients for their growth, simultaneously aiding in the purification of the water. Eventually, the water is transferred to a reservoir and subsequently returned to the fish cultivation system through pumping.
The fish that are raised include:
- Striped bass
- Tilapia
- Trout
- Catfish
- Goldfish
- Koi
The plants that are included in the hydroponic unit consist of:
- Leafy vegetables like Chinese lettuce, cauliflower, basil, microgreens, kale,
- Small plants like strawberries and cherry tomatoes
- Herbs
It is crucial to highlight that the nutrient requirements for plants grown in aquaponics are extremely minimal.
Components of an aquaponics system
- Fish tanks
This is the location where the fish are bred and reside. The tanks are typically constructed from plastic and can either be rectangular or circular in shape. The ideal water conditions necessary for fish growth, such as pH, oxygen levels, and temperature, are consistently maintained. To ensure adequate oxygen supply, an air stone is placed in the water, and feeding occurs regularly at set intervals.
- Biofilter
The nitrifying bacteria (nitrosomonous and azotobactor) and fungi break down water from the fish tank, which contains nitrous waste and uneaten food, into simpler compounds. Additionally, any excess solids are eliminated at this stage. Subsequently, the water is transferred to the hydroponic unit by pumping it.
- The water pump
The purpose of this is to move water throughout the system and deliver it to the individual components.
- Hydroponic unit
Aquaponics utilizes major hydroponic systems that are used for growing plants. This is the location where the plants are grown.
- Deep water raft system
This system is widely used and popular, even among commercial aquaponics farms. In this system, the plants are placed in a large container where they float on a foam raft structure. The roots of the plants hang into the nutrient-rich water from the biofilter, which flows at the bottom. Mesh pots support the roots of the plants.
- Nutrient film technology
The nutrient water from the biofilter is directed to flow down a sloping channel, allowing the plant roots to absorb the nutrients.
In commercial indoor vertical farming, the NFT system is utilized to cultivate leafy vegetables. The plants are positioned in a row with equal spacing, having their crown situated above and their roots placed in a channel. Mesh pots are occasionally employed to provide support for the plants, while in certain cases, media such as gravel may be utilized to support the roots.
- Media filled beds
In this process, containers are filled with porous stones or clay pellets to help plants grow. The system is supplied with water from the biofilter in order to provide nutrients for plant growth.
- Vertical aquaponics
Plants are grown by stacking them in rows on top of each other using tower systems, PVC NFT pipe channels, and vertical deep water culture units.
Why aquaponics is better than organic
- Bottom Line: There is no cheating on this with aquaponics, because we can’t use chemical pesticides of any kind or our fish would die, period.
- Even the most approved organic pesticides would kill our fish. The fish act as the “canary in the coal mine”, and force the aquaponics farmer to be honest. Even our tap water contains chloramine, which is an additive much like chlorine that would kill our fish.
- Aquaponics mimics the natural symbiotic relationship between fish & plants.
- Even traditional organic farms need to supplement their soil with fertilizers. These fertilizers can be bad for the overall health of the soil and watershed.
Environmental
- Water Conservation: Aquaponics uses 90% less water than traditional farming. Water and nutrients are recycled in a closed-loop fashion which conserves water.
- Aquaponics Protects Our Rivers & Lakes: No harmful fertilizer runoff into the watershed. In efforts to maintain nutrient-rich soil, farms have to use a lot of fertilizers. Those excess fertilizers eventually make it into the rivers, where there are countless harmful side effects.
- Gas Conservation: “Food Miles” are greatly reduced. Our produce only travels less than five miles from farm to consumer. Only serving the local community reduces harmful gas emissions.
- Energy Conservation: Even with grow lights, we use less energy than conventional commercial farming! All energy used in aquaponics is electrical, so alternate energy systems such as solar, wind, and hydroelectric can be used to power our farm.
- Land Conservation: Our system grows six times more per square foot than traditional farming.
- Farmers who are able to utilize abandoned warehouses are using structures that already exist, saving money, energy, and other valuable resources.
Health & Nutrition
- The natural self-fertilizing system of aquaponics comes from cold-blooded fish, which do not carry E. coli or Salmonella (unlike some fertilizers from warm-blooded animals).
- Fish is the fastest converter of plant protein to animal protein.
- Fish have no growth hormones, no mercury, no antibiotics, and no P.C.B.s
- Plants have no antibiotics.
- Produce tastes better than that purchased at the grocery store (because it is not shipped and stored for extended periods of time).
Farming Technique
- This proprietary system grows six times more per square foot than traditional farming.
- Aquaponics uses 90% less water than traditional farming.
- With our system, we can grow any time of year, in any weather, anywhere on the planet.
- Because aquaponics recycles the water in the system, we can grow in droughts and areas with little water.
- Fewer pests to deal with when growing indoors.
- There’s no weeding!
- Plants Grow Twice As Fast! Due to the naturally fortified water from the fish.
- For the commercial farmer, aquaponics produces two streams of income, fish, and veggies, rather than just one.
- Aquaponics farms do NOT require farmland with fertile soil, or even land with soil; aquaponics can be done just as successfully on sand, gravel, or rocky surfaces, which could never be used as conventional farmland.
