Hydroponics vs Aquaponics
As the words hydroponics and aquaponics have a similar meaning, there is always a doubt whether there is any difference between the two or are they the same. In fact, there is some difference between hydroponics and aquaponics, which are techniques used to cultivate plants in the modern world. Aquaponics is a method that uses basic hydroponic techniques to grow plants. The basic difference between hydroponics and aquaponics is the type of water used in the system; i.e. aquaponics use fish raised water instead of the nutrient solutions used in hydroponic systems.
What is Hydroponics?
Hydroponics is a technique of growing plants in nutrient solutions that contain water and fertilizers with or without using an artificial medium such as sand, gravel, coir etc. Since hydroponically grown plants are not embedded in a soil medium, they absorb required nutrients from the provided nutrient solution given. Artificial medium provide mechanical support, aid moisture and retain nutrients.
There are six basic types of hydroponics systems depending on the nutrient supplying method. They are as follows:
• Wick system
• Water culture system
• Ebb and flow (flood and drain) system
• Drip systems (recovery/ non- recovery)
• Nutrient film technique (NFT)
• Aeroponic system
Except for NFT and the aeroponic system all the other systems use growing substrates such as coarse sand, sawdust, perlite, vermiculite, Rockwool, expanded clay pellets, coir (coconut fibers).
In wick system, nutrient solution is drawn into the growing medium from a reservoir with a wick. In water culture system, a platform made of Styrofoam holds the plant and floats on a nutrient solution containing reservoir. In the ebb and flow method, first plant holding tray/platform is temporarily flooded with the nutrient solution and then solution is drained off to the reservoir. This is performed using a submerged pump connected to a timer. In drip systems, nutrient solution is dripped onto the base of each plant with the help of a pump and a timer. In NFT, continuous flow of nutrient solution is supplied into the plant containing platform so that solution flows over the roots continuously. In aeroponics, roots are kept inside a moist containing chamber that provides mist of nutrient solution directly to root system.
What is Aquaponics?
Aquaponics also can be considered as a hydroponic system. However, in aquaponics fish raised water is used as the nutrient solution for the plants. In this method, water in aquaculture tanks (fish tanks)are pumped to plants containing reservoirs. These reservoirs contain bacteria that can convert ammonia and nitrite in the fish water to nitrate. Plants take up this nutrient rich water and filtered clean water is again returned to the fish tanks.
Fish types that are used for this type of system includes: aquarium fish (Goldfish, Guppies, Koi, Tetra, etc.), Tilapia (commonly used), Trout, Carp, Freshwater Prawns, etc.
Bacteria used to convert chemicals include; Nitrosomonassp. and Nitrobactersp.
Some of the crops that can be grown using this method involves the following: Vegetable crops such as lettuce, beans, spinach, cucumber, etc., herbs such as, basil, thyme, lemongrass, parsley, etc. Fruits such as strawberries, watermelon, tomatoes and most garden varieties of flowering plants.
Filtered water from the hydroponics system drains into a catfish tank for re-circulation
Aquaponics can be considered as more sustainable ecosystem that facilitates symbiotic relationship between fish and plants. That is plants can take up water that is purified by bacteria for their growth while acting as natural filter to fish.
What is the difference between Hydroponics and Aquaponics?
• Both systems use nutrient containing solutions of water as the growing medium.
• In hydroponics, fertilizers and other nutrients should be added to water to prepare a nutrient solution. However, in aquaponics fish raised water is used as nutrient solution.
• Therefore, hydroponics is more expensive compared to aquaponics.
• In hydroponics, no bacteria is involved. In aquaponics, bacteria is used to convert the chemicals in fish water to nitrates.
• In hydroponics system, water cannot be recycled however in aquaponic system water can be recycled to fish tank to plants to again fish tanks.
Therefore, it can be concluded that Aquaponics is a method that has derived from hydroponics and it is an inexpensive and efficient method to obtain nutrient solution. Also, it is an eco- friendly method to grow plants and aquaculture.
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