Hydroponics is the process of growing plants in water instead of soil in an indoor environment. Researchers use the process to evaluate the amount of nutrients absorbed and used by a plant. Hydroponics allows a gardener to grow crops year-round without worrying about seasons or weather restrictions, and there is a lower risk of plant disease.
The word hydroponics comes from the combination of the Greek words "hydro" for water and "ponics" for labor. The Hanging Gardens of Babylon were created with hydroponics, so the concept has been around for thousands of years. The first noted experiments by scientists started in 1950. Several European countries have taken the concept of hydroponics for crop productions with great results.
The top benefit of growing in hydroponic conditions is that plants will grow 30 percent to 50 percent faster than in a soil medium. Plants also yield greater quantities. The reason for this is that the roots are able to absorb more oxygen due to being exposed. Nutrients are also absorbed more quickly as the water used for hydroponics is directly infused with nutrients. This allows the plant to exert less energy and put the energy stores into fruit and vegetable production.
Hydroponic systems are either active or passive and available in several styles. The wick style is a passive system that involves no moving parts or pumps. This system uses a growing medium that acts like a candle wick to bring nutrients to the root system. While the wick system is not the most effective for hydroponics, it is low-cost and easy to maintain. An ebb and flow system is an active system that uses a pump to move water through a reservoir that holds the roots. A continuous-drip system is active and involves a pump that delivers a continuous flow of water to the roots. Each plant has a water line that delivers the drip of water. A catch tray below the plants returns excess water back to the reservoir for reuse.
A growing medium is required in some types of hydroponic systems. The wick system uses a medium that contains perlite or sand with vermiculite. The downside of this mixture of growing medium is that it holds too much water and makes the environment too wet. The ebb and flow system uses a medium of either rockwool or grow rocks. Rockwool is created from volcanic rock that is molten and spun similar to making cotton candy. Grow rocks is a reusable medium made from aggregate clay or expanded shale. A brand name for grow rocks is Hydroton.
Hydroponics supply stores sell a concentrated nutrient solution that gives the plants the same elements found in soil. There are generally two types of nutrient solutions applied, one for blooming and one for production. The nutrients are available in powder or liquid and are mixed with water for plant application. The minerals in the concentrate will cause clogging of pumps and tubes, so regular maintenance of equipment is needed.