Types Of Aquaponics Designs
Primarily, there are three different types of aquaponics system designs; Nutrient Film Technique (NFT), Media Bed, and Deep Water Culture (DWC). Although these are not the only three designs, they are the most common and what we utilize here at ECOLIFE.
When deciding what type of system to build, it is important to weigh the pros and cons of each design in order to determine what fits best with your needs and capacity.
Questions To Ask Before You Start Your Design:
It is important to think about the intended use of the system. Whether it’s for personal, educational, or commercial use, your intentions will ultimately determine what kind of system is needed. You must also think about:
- Space/Scale: How much space do you have? Do you need to maximize it? How much do you intend to produce, for whom, and what purpose?
- Type of crop: Type of crop: You have to match the system to the crops. Temperature ranges, nutrient demands, growth rate, weight, and root zones are all important factors in design selection.
- Environment: Environment: Annual, seasonal, and daily temperatures fluctuations will directly affect productivity of the different life forms and ultimately the design of your system. Will you want to absorb or exchange heat? Is it inside or outside?
- Technical capabilities: Technical capabilities: Each design has characteristics that lend themselves to different levels of expertise. Who will be using and managing it, and how much do you need to know about food production and aquaculture techniques?
Nutrient Film Technique
FT systems are popular in the commercial industry because of their space efficiency and lower labor costs. Because crops can also be grown on a vertical plane (or shelf), they are easily accessible and harvestable. Most popular with hydroponic production, this method is best suited for leafy greens. This design is not suited for large fruiting plants as their root masses may clog the channel and their weight may not be supported. The plant roots are exposed to more air and less water in an NFT system which can leave the plants vulnerable to extreme heat or cold fluctuations.
• Continuous supply of water, oxygen, and nutrients
• Space efficient
• Easy to access
• Lower labor inputs
• Susceptible to clogging
•Higher possibility of water temperature fluctuation
• Not suitable for larger or flowering plants
The media bed form of aquaponics uses containers filled with rock media such as gravel or expanded clay (hydroton) to support the roots of plants. The bed is flooded and drained of nutrient rich water to give the plants the nutrients and oxygen they need. The media used to support the plants acts as both a mechanical and biofilter to capture and breakdown wastes.
This technique is best used for backyard gardeners and beginners because it does not require an engineering, aquaponics, or plant science background to function well. It is inexpensive, simple to put together, and productive at small scale. Because the media supports the plants like soil would, you are able to produce large root mass plants such as fruits, flowering plants, vegetables, and root vegetables. Because the media is not space efficient and requires considerably more inputs of labor, media bed designs are hard to scale into commercial use.
• Grows larger crops well
• Good biofiltration
• Simple and inexpensive to implement
• Media acts as filtration
• Great for smaller scale system
• Tough to scale for large production
• Requires more cleaning
• Higher maintenance and labor
Deep Water Culture (DWC)
Also known as raft or float systems, this method uses floating rafts to suspend plant roots into nutrient rich and aerated water. The plant roots float directly into a pool of water about 1 foot in depth. Since there is no media to capture and process the solid wastes, filtration techniques must be built into the design. This necessitates more advanced aquaculture techniques and system requirements, leading to higher upfront costs.
This design is common with commercial production as it is the most stable of the three system types. Because there is much more water in the system, drastic nutrient and temperature fluctuations are much less likely to occur. It is best suited for warmer climates because although it would resist daily temperature swings, heating the water in colder climates is costly. In addition, larger root zone plants can be used and removing plants is much easier than in media beds.
• Commercial scalability
• Good for warmer tropical climates
• Not as susceptible to large temperature and nutrient fluctuations
• Filtration demands
• Labor demand and cost
• Space efficiency