In Latin, the word hydroponics means literally "water working."
Hydroponics is the practice of growing plants in either a bath or flow of highly oxygenated, nutrient enriched water.

In soil, biological decomposition breaks down organic matter into the basic nutrient salts that plants feed on. Water dissolves these salts and allows uptake by the roots. For a plant to receive a well balanced diet, everything in the soil must be in perfect balance. Rarely, if ever, can you find such ideal conditions in soil due to the lack of organic matter left behind on the surface, contamination and biological imbalances.

With hydroponics, water is enriched with these very same nutrient salts, creating a hydroponics nutrient solution that is perfectly balanced. And since this hydroponics nutrient solution is contained, it does not harm our environment as does runoff from fertilized soil. Additionally, very little water is lost to evaporation in a hydroponics system, owing to its application in drought stricken areas.

To support the plants in a hydroponics system, an inert soil-free medium like fiber, sand or stone, may be used to anchor the roots. These hydroponics mediums are designed to be very porous for excellent retention of air and water that's necessary for a healthy plant - roots need to breathe too!

In addition to a perfectly balanced diet, hydroponics plants have their food and water delivered directly to their roots. This way, the energy normally used to develop long roots can be redirected to growing more plant, which is a great benefit indeed! With the proper exposure to natural sunlight or supplemental grow lights, the hydroponics plants grow.

Nutrient film technique is one of the more popular systems for hydroponics
A film of nutrient solution flows along a channel. Part of the root system down into the nutrient solution polythene trough and part grows above the water level, receiving air. The support surface for the polythene is gently sloped to provide a continuous gradient down which the solution will flow forming a ‘film’ only about 1mm deep. The system is used to grow tomato, lettuce, spinach and some herbs.

The nutrient film technique is one way of growing crops in desert areas. However, the expense of the technical facilities and maintenance may take the system uneconomic in practice.

Advantage of hydroponics:

1. A well-managed hydroponics system can produce greater yields than traditional soil-based systems. Because hydroponics systems are generally inside greenhouses, where they are protected from insects and other plant pests.

2. Plants grow faster because their roots are supplied with nutrient solution all of the time. Lot of root growth to find nutrient in short supply is not necessary.

3. Weeds are eliminated, reducing the workload of farmers and cutting out the need for herbicides.

4. Insects’ pests which live in the soil are eliminated, reducing the need for insecticides.

5. Quality and taste are better because the plants are supplied with all of the nutrients they need.

Disadvantages of hydroponics:

1. Many of the disadvantages of hydroponics systems have to do with cost:
1. the initial construction cost;
2. the costs of maintaining equipment and greenhouse facilities;
3. the costs of nutrients and
4. the salaries of trained personnel for constant monitoring for nutritional problem and waterborne disease

2. Most hydroponics farms concentrate on a single plant species, a practice known as monoculture that brings a risk of the rapid spread of disease, whether the monoculture is hydroponics or land-based.