Hydroponics is defined as 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 either water-based or medium-based. Examples of media-based systems are the wick system and the ebb and flow 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 hydroponics include: water culture, drip, and nutrient film technique (NFT). 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 that collect the nutrient liquid back into the reservoir are known as recovery systems. If the nutrient liquid is not reused, it is known as a non-recovery system. Plants in water-based hydroponics are vulnerable during a power loss or equipment failure.
The nutrient solution is an important part of the hydroponic system. Plants in a hydroponic system do not have access to the food provided in soil; they need to be fed through a nutrient solution. It is critical to purchase a nutrient fertilizer that is specific for hydroponics and follow the dilution rate recommended. Test the pH of the solution often to be sure it is between 5 and 6.
Other Growing Requirements
There are other growing requirements for the plants in a hydroponic system. In addition to feeding the plants, they need oxygen. An air stone and air pump will oxygenate the liquid nutrient. Plants need light to grow. Virginia State University Extension specialists state 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.
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 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.