Hydroponics is the practice of growing plants without soil. Most commonly, hydroponics cultivates plants in nutrient-rich water, although hydroponics can also be considered to be the practice of growing plants in other aggregates, such as a soil-less bark-based mix. Hydroponics is an advantageous method of gardening both for home and commercial use. There are no weeds to deal with, and hydroponic plants are typically more healthy, mature earlier, and use less space.
In addition, because it is entirely water-based, it is possible to fully automate a hydroponics system, so if the gardener is absent for an extended period of time, the plants will not suffer. The water is typically reused, as opposed to traditional farming methods where much water is lost through evaporation or runoff.
In an indoor hydroponics system, plants may receive sunlight through artificial means such as grow lights. Another consideration for indoor hydroponic gardens is air circulation. This prevents fungal diseases and allows the plants to draw out the necessary carbon dioxide they require.
The most important factor in hydroponics however, is the nutrient solution that must be mixed with water. Standard fertilizers are inadequate, because they lack some of the elements necessary that the plants would otherwise derive from the soil. Specially-formulated hydroponic fertilizer mixtures are required. These are widely available, but should be tested after dilution to ensure a pH of between 5 and 6. The nutrient solution should be changed every two weeks. In between changes, make sure that the volume is kept level by adding more water only, and not additional fertilizer formula. If water evaporates and the water level gets too low, the nutrient solution will become too rich and could actually burn roots.
There are three different ways of culturing hydroponically-grown plants. The simplest one, the nutrient film technique, simply uses a plastic trough as a container. Holes are placed in the top to hold the plants. The trough is sloped slightly, so the solution will flow to a reservoir.
Other methods include aeroponics, which suspends the roots in a mist rather than a solution, and aeration, which uses an air pump to deliver oxygen to the roots that are immersed in the solution.
An aggregate system of hydroponics uses inert material, such as clay pebbles or foam chips to surround the roots and provide support to the plant. The most common aggregate system is the flood and drain method, which fills a container with the aggregate. The container is then flooded with the nutrient solution as often as necessary.
Hydroponics systems are easy to set up for a home gardener, and can produce an excellent yield of quality plants. Equipment is not expensive, and systems can even be home-made from common materials that can be found in any hardware store.