The deep water culture can be considered the easiest to manage of all the aquaponics systems that aspiring growers can do. This soilless method could be executed using minimal and easy-to-find materials. Additionally, the raft system does not require much maintenance and can handle sudden power interruptions.
What are the different systems in aquaponics?
Aquaponics is a production method that combines hydroponics and aquaculture. The added fish food serves as the system's input in aquaponics. When fish consume and digest food, they produce ammonia-rich urine and feces, which, in large enough quantities, can be hazardous to both plants and fish.
After that, the water from the fish tank passes into a biofilter along with uneaten food and decomposing plant materials, becoming now ammonia-rich. Bacteria then convert everything into organic nutrient solutions (nitrogen-rich for growing plants) inside the biofilter.
Now that we know the essential operation of aquaponics as a food production mechanism, we will have to acquaint ourselves with its three setups. These are the deep water culture, nutrient film technique, and media-based aquaponics.
Deep water culture
Description: In deep water culture, rafts made of polystyrene or foam board float on top of the nutrient-rich water that circulates through the long canals at an average depth of 20 cm. The plants are cultivated on raft boards supported by net pots inserted into holes. Hanging down in the nutrient- and oxygen-rich water, plant roots take in these elements and grow quickly. The nutrient-rich water continuously circulates from the fish tank to the filtering system, then to the raft tank where the plants are grown, and then back to the fish tank. The raft tank is often kept apart from the fish tank.
- Since there is more water in a raft system than in other setups, it offers the most stable water quality and temperature.
- It is a suitable system for commercial production, recreational uses, and backyard gardening.
- The plants' root system has enough exposure to essential nutrients.
- Some consider this as the most affordable and straightforward aquaponics system to construct.
- Since roots are not in any substrate and are instead submerged in water, plants are easier to harvest.
- The deep water culture is recognized as a cost-effective system.
- Evaporation could occur between the raft's borders and the tank where the system is housed in.
- Roots are vulnerable to microbial contamination or could be eaten by fish that eat plants.
- The system under consideration is only capable of producing small leafy greens like basil and lettuce.
- There is a minimal surface area available for the growth of helpful microorganisms.
- Fish tank: This item keeps the aquatic species of the system, which are commonly fish.
- Grow canals: Since so much water is needed in this system, canal lengths can range from one to ten meters, ensuring a sufficient supply of nutrients. 30 cm is the suggested depth to provide enough room for plant roots. Canals should be constructed from any sturdy material which can hold a large volume of water, similar to the fish tanks.
- Floating rafts: The plants will grow in this area. Styrofoam or another lightweight material is used to prepare floating rafts, which are then lined with foam. Plants are inserted into holes on the rafts so the roots can hang over the water. Net pots are frequently utilized to improve stability and keep the plants from falling through.
- Water pumps: A dependable aquaponics pump is necessary to circulate water throughout the system in an aquaponics setup continuously. Water is pumped from the fish tank to the plants, then back to the fish tank.
- Filter: This component is critical because solid particles, leftover fish food, and fish excrement can seriously damage your aquaponic system. The filters deal with any solid waste, plant matter, and anything else that might enter the system.
- Biofilter: The biofilter is a colonization site for the beneficial bacteria needed in aquaponics setups. Here, the helpful bacteria convert fish excrement into nutrient-rich, useable food for the plants.
Nutrient film technique
Description: Also called by its acronym, NFT, the nutrient film technique offers a straightforward yet effective design for aquaponics. This approach works well in many settings and offers numerous benefits to the grower. In NFT, horizontal pipes are a significant component, and here, shallow streams of nutrient-rich water freely flow. Holes on top of the pipes are provided; these are also the spaces allotted for the plants to grow.
- The plants' roots receive plentiful of their needed oxygen, making them properly oxygenated.
- Since water continuously flows in NFT, solid waste build-up within the system is effectively prevented.
- The roots are protected from fungal growth thanks to the consistent water movement inside the PVC pipes.
- There is a possibility that roots can clog the channels, especially if the plants have a rich fibrous root system.
- Water temperature can quickly fluctuate in the nutrient film technique because the flowing water is very thin.
- Growers can only cultivate a limited number of crops using NFT.
- Fish tanks: These are the containers that house the preferred aquaponics fish.
- Water pump: The water travels across the aquaponics components thanks to the installed water pumps.
- Sump tank: This component collects all the water drained from the grow beds, which is returned to the fish tank.
- PVC pipes: These parts are used to contain the chosen aquaponics plants. Roots are allowed to dangle to make contact with the flowing water inside of the PVC pipes.
- Rubber hoses, PVC tubings, and fittings: These components are put together to ensure water flows appropriately across the nutrient film technique setup.
Description: The most popular design for small-scale aquaponics is the media-filled bed units. In this approach, the medium serves as a mechanical and biological filter in addition to supporting the plants' roots. Due to their simplicity and space-saving efficiency, these designs are suitable for novices and have a minimum initial investment. For the majority of emerging regions, this approach is strongly advised.
- This type of soilless gardening requires minimal cleaning.
- It allows the utilization of recycled materials.
- The media-based setup is perfect for those who aim to use aquaponics as a hobby application.
- You can modify the media-based specification to meet your needs.
- A wide range of plants grows in a medium-dependent aquaponic system.
- Certain high-quality growing mediums can be expensive.
- Due to its reduced productivity and difficulties in implementation on a big scale, this form of aquaponics is typically not appropriate for commercial use.
- The media beds require a robust and sturdy structure because they could become heavy.
- Fish tank: Aquaponics requires the use of fish tanks. In the fish tank, your fish will reside, and for them to survive and thrive, specific criteria must be met. Therefore, care should be taken in selecting the fish tank. When choosing your fish tank, there are some crucial factors to consider.
- Grow bed: This factor is one of the essential parts of the media bed system. Remember that your plants will develop in the grow bed, so be sure it is constructed of food-grade materials that will not leach harmful chemicals into the water or alter the pH levels.
- Grow media: It is essential for the media to be organic and have enough surface area for bacteria to thrive and for water to reach the roots of the plants. To ensure the water quality is unaffected, the medium needs to have a neutral pH. Before adding the media to your grow bed, it's a good idea to carefully wash it to remove any potentially harmful particles for the fish.
- Bell siphon: An aquaponics system based on media must include a bell siphon. This specific equipment controls the water flow throughout the entire system and effectively assists in transferring the water from the media bed into the fish tank.
- Water pump: Failure to maintain your aquaponics system could result if your water pump is not dependable enough to disperse the water in the system.
Which aquaponics' system is easiest to set up and maintain?
Of the three systems I mentioned, I consider the raft system the easiest to set up and maintain. There are several reasons for this.
- Deep water culture systems are straightforward to set up and only need a small number of elements, which you can assemble quickly. The only moving component is an air pump, which is a simple apparatus to operate.
- Once you set up the system, upkeep is cheap and requires little effort.
- Comparatively speaking to other aquaponics setups, the initial costs of setting up a small DWC system are meager.
- Compared to the NFT technology, irrigation is unaffected by power outages.
- You don't need to be concerned about a power outage or equipment failure because the DFT systems can keep adequate water.
- The nutrient solution is restricted to a single plant in a straightforward DWC arrangement, aiding in containing any deadly outbreaks of root disease.
What is challenging about aquaponics?
Despite being an innovation in food production, aquaponics poses specific challenges any aspiring growers should deal with. These can be categorized into two: Technical and socio-ecological challenges.
The aquaponics practitioner should be aware of system-specific requirements that affect the performance of the setup he is utilizing. Aside from this, knowledge about financing and marketing should be considered, especially if the aquaponics system is created for commercial purposes.
What are the most common reasons for aquaponics systems to fail?
Every aquaponics system will inevitably encounter issues, and failing to address them could result in losing the fish and plants you've been raising for weeks. This can also leave you with the disheartening impression that you wasted time, money, and resources building up your aquaponics system. Understanding the most typical aquaponics issues and how to resolve them is crucial.
- Dying plants: This should be the top concern of any aquaponics grower because it could affect the system's harvest. Several explanations could be cited to explain this issue: insufficient supply of oxygen and water, improper pH levels, and the presence of pests.
- Dead fish: In an aquaponics system, dead fish occasionally occur; however, if there is more than one dead fish, you should be concerned about your system. The ammonia level needs to be checked first under this problem. You must regularly check your ammonia levels since too much can kill your fish.
- Fish overstocking: Your system will become less effective if your fish tank is crowded with too many fish. If starting your system, it is best to avoid filling your fish tank and keep the stocking density modest. A decent general rule of thumb is that one fish should be kept for every eight gallons of water.
- Presence of pests: Unwanted insects can be an issue in aquaponics, just like in any farming technique. For this reason, it's crucial to consider using natural pest management when setting up and maintaining your system. To resolve this issue, you can use bug netting to physically surround your growth and keep numerous pests away from them.
- Algae growth: When they become out of control, algae can be a concern in aquaponic systems. Green algae are the most typical algae that pose issues in aquaponic systems. Because algae can alter your system's nutrients and pH if improperly maintained, precautions must be made to prevent it.