Hydroponics is a subset of hydroculture and is a method of growing plants using mineral nutrient 

solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient

solution only or in an inert medium, such as perlite, gravel,biochar, mineral wool, expanded clay pebbles or coconut husk.

 

Advantages of Hydroponics

 

Some of the reasons why hydroponics is being adapted around the world for food production are

the following:

• No soil is needed for hydroponics.

• The water stays in the system and can be reused - thus, a lower water requirement.

• It is possible to control the nutrition levels in their entirety - thus, lower nutrition requirements.

• No nutrition pollution is released into the environment because of the controlled system.

• Stable and high yields.

• Pests and diseases are easier to get rid of than in soil because of the container's mobility.

• Ease of harvesting.

• No pesticide damage.

 

Techniques

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There are two groups of techniques for hydroponics:

 

• Passive technique: the nutrient solution is stationary and the plant takes what it needs

• Active technique: the nutrient solution is rinsed or atomized along the roots 

 

The application of passive or active hydroponics depends on the use: passive techniques are more suitable for growing on a small scale, e.g. house plants in the living room, while the active techniques more suitable for large scale cultivation.

 

How does it work?

 

The basic principle is simple:

 

• The plant grows in a special substrate for hydroponics of porous rock, wool or another inert
  and non-rotting material.

• The water is in a reserve at the bottom of outer pot or in a separate tank. The plant is not in
  the water but above it (or next if you have a separate tank). Thanks to a water meter you can
  check visually how much water remains in the tank.

• The hydroponic fertilizers are specifically designed to be dissolved in the water.

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Besides this basic principle, there are many variations in substrate and in the way the water arrives at the roots, also depending on the use as houseplants, office plantings or horticulture.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Information Source: Wikipedia & All About Hydroponics Blog