Hydroponics means growing plants in water and a nutrient solution instead of soil. There are several advantages to growing plants in this manner. The crop requires less space and no soil. There are also no soil diseases or insects to infect the crop. Plants require less water and no cultivation. Organic and biological control of disease and insects are less costly and easier because the system is enclosed. Best of all, there is no weeding.
Hydroponic growing is divided into two groups, water-based and medium-based. In a medium-based system, a growing medium--such as rockwool, perlite or vermiculite--is used at the root of the plant to help hold the nutrition. Media-based hydroponics is generally considered to be more expensive because of the cost of the media. However, media-based systems are capable of surviving short power outages because the media keeps the roots moist.
Water-based systems require a continuous flow of both water and nutrient solution, since there is no media to hold and store liquid. Water-based hydroponics where the nutrient liquid is collected back into the reservoir are known as recovery systems. If the nutrient liquid is not reused, it is a non-recovery system. Plants in water-based hydroponics are vulnerable during a power loss or equipment failure because no water can flow to the roots.
The nutrient solution is an important part of the hydroponic system, says the Virginia Cooperative Extension. The plants in a hydroponic system do not have access to the food provided by soil, they need to be fed through a nutrient solution. The Extension recommends home gardeners purchase a nutrient fertilizer that is specific for hydroponics and follow the dilution rate on the packaging. Test the pH of the solution often to be sure it is between 5 and 6.
Other Growth Requirements
Plants in a hydroponic system have other growth requirements. In addition to nutrients, the plants need oxygen. An air stone and air pump can oxygenate the liquid nutrient. Plants need light to grow. Virginia Cooperative Extension suggest that metal halide lamps, gro-lights and fluorescent lights can provide adequate lighting if natural sunlight is not an option. Air circulation is also important as it prevents disease.
Choosing a System
Choose the system that works best for the space available, the time you have to invest and what you want to grow. Media-based systems cost more money to maintain. Water-based systems require more time to maintain, although some of the work can be completed through timers. Systems that use a wick to move the nutrient feed are generally not suited to large plants or long rooted plants; instead use drip systems or flood-and-drain type systems. Any of the hydroponic systems are good for greens, oriental vegetables, herbs and edible flowers. Ebb-and-flow systems or drip systems work well for peppers and tomatoes.