Difference Between Hydroponics and Aquaponics

Main Difference – Hydroponics vs Aquaponics

Hydroponics and aquaponics are two methods used in agriculture to grow crops without soil. Aquaponics is a type of hydroponics. Both systems use a nutrient-containing water solution as the growth medium. The main difference between hydroponics and aquaponics is that hydroponics is the cultivation of plants in water whereas, fish and bacteria is used in combination with plants in aquaponics. Chemical compounds are used as nutrients in hydroponics. However in, aquaponics, a looped system, in which the fish waste is converted into nutrients by the action of bacteria, is produced. Therefore, aquaponics is more eco-friendly and efficient than hydroponics.

Key Areas Covered

1. What is Hydroponics
     – Definition, Facts
2. What is Aquaponics
     – Definition, Facts
3. What are the Similarities Between Hydroponics and Aquaponics
     – Outline of Common Features
4. What is the Difference Between Hydroponics and Aquaponics
     – Comparison of Key Differences

Key Terms: Aeroponics, Aquaponics, Fish Waste, Hydroponics, Nutrients, Soil, Water

What is Hydroponics

Hydroponics refers to the cultivation of plants in water. But, the medium used in hydroponics does not contain the essential nutrients for the growth of plants as in soil. Therefore, in hydroponics, the roots of the plants are dipped in a nutrient-containing water solution. Different types of hydroponic methods can be identified as aeroponics, aquaponics, deep water culture, ebb and flow system, nutrient film technique, and Wilma systems. The roots of the hydroponic vegetable system are shown in figure 1.

Figure 1: Roots in Hydroponic Systems

Aeroponics

In aeroponics, a high-pressure, nutrient-rich mist is used to feed plants, providing more balanced water, nutrients, and oxygen supplements to the roots. Roots require oxygen for better absorption of nutrients. Aeroponics is used in the NASA space station to grow plants. A schematic representation of an aeroponic system is shown in figure 2.

Figure 2: Aeroponic System

In hydroponics, oxygen is provided to the water by pumping it with air pumps. The hydroponic systems can be used at home as well as commercially. It produces a high yield and high growth speed of plants. The major drawback of hydroponics is the high cost of nutrients and high maintenance cost.  

What is Aquaponics

Aquaponics refers to a branch of hydroponics in which a combination of fish and plants is used in a looped system. In addition to synthetic fertilizers, fish excrement is used as the source of nutrients in aquaponics. On that account, aquaponics is one of the most organic options for hydroponics. Aquaponics with catfish is shown in figure 3. The filtered water from the hydroponic system drains into a catfish tank for re-circulation.

Figure 3: Aquaponics with Catfish

Aquaponic systems produce a high yield of crops; meanwhile, fish can be harvested from the system. The fish can be fed with unwanted parts of vegetables. Fish waste can be used as the source of nutrients. The conversion of the fish waste to organic nutrients is done by bacteria. This water can then be pumped to the root zone of the crops. As organic nutrients are used in aquaponic systems, a balanced nutrient supplement is provided to the crops. However, some parameters can be optimized such as pH of the medium. 

Similarities Between Hydroponics and Aquaponics

• Hydroponics and aquaponics are two methods used in agriculture to grow crops without soil.
• Both hydroponics and aquaponics are involved in the plant growth on the water by supplying nutrients.
• All nutrients should be artificially provided to the crops as the soil is not used in both methods.
• Both hydroponics and aquaponic systems are stable and produce high yields.
• No damage occurs from pests in both hydroponic and aquaponic systems.
• Lower water and nutrient levels are required by both hydroponic and aquaponic systems.

Difference Between Hydroponics and Aquaponics

Definition

Hydroponics: Hydroponics refers to the cultivation of plants in water.

Aquaponics: Aquaponics refers to a branch of hydroponics in which a combination of fish and plants is used in a looped system.

Type of Nutrients

Hydroponics: Chemical nutrients are used in hydroponics.

Aquaponics: Organic matter produced by fish wastes is used as nutrients in aquaponics.

Usage of Bacteria

Hydroponics: The bacterial growth is inhibited in hydroponics.

Aquaponics: The bacterial growth is used in the production of nutrients from the fish waste.

Temperature

Hydroponics: Hydroponic systems are maintained at low temperatures, inhibiting the bacterial growth.

Aquaponics: Aquaponic systems are maintained at temperatures that induce the growth of bacteria.

Startup Speed

Hydroponics: The hydroponic systems are faster.

Aquaponics: The aquaponic systems are slower than the hydroponic systems.

Cost of Nutrients

Hydroponics: Hydroponic systems are less cost-effective as chemical nutrients are used.

Aquaponics: Aquaponic systems are cost-effective as organic matter is used as the source of nutrients.

System Unloading

Hydroponics: Hydroponic systems should be unloaded after a certain period of time due to the buildup of slats and toxic chemicals.

Aquaponics: As natural nutrients are used in aquaponic systems, the replacement of water in the system is not required.

Productivity

Hydroponics: Hydroponic systems have a less productivity.

Aquaponics: Aquaponic systems have a high productivity.

Ease of Maintenance

Hydroponics: Hydroponic systems are difficult to maintain when compared to aquaponics.

Aquaponics: Aquaponic systems are easy to maintain.

Conclusion

Hydroponics and aquaponics are two types of methods used in agriculture to grow plants on water. Chemical nutrients are used in the form of fertilizers in hydroponics while fish waste is used as the source of nutrients in aquaponics. The main difference between hydroponics and aquaponics is the type of nutrients used in each type of methods.

Reference:

1. “What is Hydroponic growing?” Growth Technology, Available here.
2. “What is hydroponics?” Simply Hydroponics, Available here.

Image Courtesy:

1. “Root Of Hydroponic Vegetables” by Aqua Mechanical (CC BY 2.0) via Flickr
2. “Systeme AEROPONIC 573px” By MagicBeaver – Own work (CC BY-SA 3.0) via Commons Wikimedia
3. “Aquaponics with catfish” By Ryan Somma – Aquaponics (CC BY-SA 2.0) via Commons Wikimedia