Pros and Cons of Different Types of Aquaponics Systems

Pros and Cons of Different Types of Aquaponics Systems

Aquaponics is a combination of fish farming (aquaculture) and the growing of plants in the nutrient solution (hydroponics). Aquaponics is a recirculating system in which fish are reared in a fish tank. The fish waste which the ammonia is converted into nitrates by the bacteria and become nutrients for the plant roots to absorb. The plant roots will filter the water before it returns to the fish tank for another cycle. (1)

These are the different types of aquaponics systems:

1. Media Based Aquaponics System

 The media based system is the most common type of Aquaponics system. This system is also called Flood and Drain.  In this system, plants are grown in a planting media like gravel or expanded clay pebbles. The planting media filters the ammonia-based waste and solid waste. The media based system is well suited for growing smaller and larger fruiting plants. This system is also popular with do-it-yourselves, backyard aquaponics systems, and commercial farms. (2)

Best Use:

The media based system is best used for beginners and backyard aquaponics gardeners because it is easy to set up, inexpensive, and productive at a small scale. Because the growing media can support the plants very well, you can plant large root mass plants such as fruits, flowering plants, vegetables, and root vegetables.

Pros Cons
  • Relatively simple and inexpensive.
  • A good-quality medium can be relatively expensive.
  • Suitable for all kinds of plants from leafy greens to larger fruiting plants.
  • The pore spaces in the medium may get clogged over time, causing anaerobic conditions that are poor for your plants.
  • Minimal cleaning required.
  • It can require cleaning of the grow bed.
  • The media perform a filtering action, preventing debris from returning to the tank.
  • The media beds are heavy and need a strong, rigid structure. (2)
  • The air is present between media particles, supplying oxygen to the roots.
  • Applications, home gardens, and as part of the commercial farm. (2)

2. Nutrient Film Technique

The Nutrient Film Technique (NFT) in Aquaponics is a method in which the plants are grown in a long narrow channel. NFT is a hydroponic growing technique that is adapted to aquaponics because of its simple yet effective design and works well in some environments.

In NFT, a thin film of water flows continuously down each channel, providing the plant roots with water, nutrients, and oxygen. When the water reaches the end of the channel, it is pumped back to the fish tank. (3)

Similar to the raft system and media-based system, NFT uses both water and pump to deliver nutrients to the plants. This system requires a separate filter to clear the water of solid and biological waste before it’s returned to the fish tank. 

Nutrient Film Technique systems are primarily used in cultivating greens that have small roots systems. NFT is commonly used in the commercial aquaponic system but can also a hobby system as long as the water is filtered before it is used in the NFT channel

Best Use:

NFT is popular in commercial aquaponics because of its space efficiency and lower cost of labor. Plants are easily accessible and harvestable in this system because they are grown in vertical pipes. This system is best for leafy greens and not suited for large fruiting plants as their roots may clog the channel. The plant roots are more exposed in more air and less water in the NFT system, which can lead the plants vulnerable to heat and cold fluctuations.

 

Pros Cons
  • Roots are highly oxygenated.
  • The roots can clog the channels.
  • Constant flow of water. 
  • Water temperature fluctuations.
  • Constant flow reduces fungal risk. 
  • Pump failure can destroy yield.
  • Space efficient.
  • It can only grow limited plants.
  • Easy to access.
  • Lower labor input.

3. Raft System of Aquaponics

In a raft system, also known as Deep Water Culture or Floating System, the plants are grown on rafts (polystyrene or foam boards) that float on top of the water in the raft bed. The nutrient-filled water flows continuously from the fish tank through the filtration process, then to the raft tank where the plants are grown and then back to the fish tank. Most often, the raft tank is separate from the fish tank. 

The beneficial bacteria primarily live in your bio-filter or media beds but also in the raft tank and throughout the system benefiting the plants. Plants grow quickly in a raft system and can be an easy aquaponics system for the beginner aquaponics gardener to set up and maintain.

 

Best Use:

The raft system is common with commercial production.  Many commercial aquaponics farms use this system because they allow the plants to grow faster and yield more crops. The Raft system is best suited for mass production of certain types of vegetables like leafy greens.

Pros Cons
  • High productivity of crops with low labor requirements.
  • It is restricted to growing small leafy greens like lettuce and basil.
  • The roots are more exposed to water nutrients.
  • Unsuitable for roots, some fruits, and a few other plants.
  • Simple and can be the most economical to build of all aquaponics systems.
  • It can be a mosquito breeding ground if not designed correctly. (these may be controlled by using guppies or mosquito fish)
  • Plants are easier to harvest since roots are submerged into water and not in any media.
  • Water can evaporate at the gaps between raft edges and the tank it is kept in.
  • Easy maintenance as raft beds is easy to clean. Since rafts can be placed in the tank itself, it allows for the efficient use of space.
  • Needs filtration since the roots are completely immersed.
  • It is suited for home gardens, hobby applications, and commercial production.
  • Roots are susceptible to herbivorous fish may consume microbial attacks.
  • There is little surface area for beneficial bacteria to grow.
Media Based Aquaponics System

4. Constant Height One Pump

The constant height one pump (CHOP) is sometimes called “constant height in the fish tank” (CHIFT) or a “pump in a sump tank” (PIST). This system comprises a CHOP, fish tank, sump tank, and grow beds with grow media. The pump is used to pull the water from the sump tank into the fish tank, which drains into the grow bed where plants live, each grow bed has a bell siphon. (4)

The water flows into each grow bed and rises until it reaches the top of the bell siphon and then flushes into the sump tank. Gravity causes the water to flow back to the sump tank from the grow beds and the auto-siphon helps regulate the system. Once the water flows back to the sump tank, the entire cycle can begin again.

Best Use:

Most beginners, hobbyists do-it-yourselves, and backyard aquaponics gardeners use the CHOP system of aquaponics because this is the most efficient way to run an aquaponics system. The chop system is also easy to set up and easy to maintain. This system can support small and larger plants because it uses grow media to give support to the roots. 

Pros Cons
  • The water level is always consistently maintained.
  • Media beds fill up with solids over time and have to be cleaned.
  • Can use inexpensive materials.
  • Needs a large sump tank to hold water from the grow beds.
  • Reliable
  • Easy to set up.
  • Energy-efficient.

5. Hybrid

A hybrid aquaponics system is a combination of multiple types of an aquaponics system. Most commercial aquaponics uses a hybrid system because if its efficiency and great use of space. You can combine any system that you like and fits your needs. There are several approaches to this aquaponic system and all can work well, depending on how you design, build, and maintain your system. (4)

Here are the most common hybrid approaches:

  1. CHOP system that drains into DWC bed then into the sump tank. 
  2. NFT or Vertical system that drains into a DWC bed.

These approaches use media based grow bed to provide nitrification, a solid filtration, and mineralization. These allow you to use a DWC bed without filters. It is important to size of your media based grow bed to provide a full filtration function. (4)

Best Use

The hybrid system is used mostly in commercial aquaponics and home aquaponics that wants high productivity in a small space. 

Pros Cons
  • Planting flexibility
  • More complex to set up and manage.
  • Low maintenance.
  • More expensive to set up.
  • High productivity.

What type of aquaponics system is suited to you?

Aquaponics can be simple or complicated; it depends on how you want your system to be. Educating yourself first to the pros and cons of the different aquaponics systems is important in creating a system design that is perfect for your aquaponic gardening needs and wants. Join our Facebook community for more updates about aquaponics.

Source: 

  1. https://gogreenaquaponics.com/blogs/news/what-is-aquaponics-blog
  2. https://gogreenaquaponics.com/blogs/news/aquaponics-systems-what-is-a-media-based-aquaponics-system
  3. https://aquaponics.com/methods-of-aquaponics/
  4. https://www.maximumyield.com/5-ways-to-grow-using-aquaponics/2/1331
  5. https://www.ecolifeconservation.org/updates/types-aquaponics-systems-design/