Hydroponic gardening is the practice of growing plants without the use of soil. Plants are grown in structures that support the roots, or leave the roots open to a nutrient solution that provides the food necessary for plant growth. With the addition of lights, hydroponics is possible indoors in small spaces.
The nutrient solution provides the food for the plant and is one of the most important aspects of a good hydroponic system. A nutrient solution contains all 13 elements necessary for plant growth, which is different from soil fertilizers that may only contain nitrogen, phosphorous and potassium. The pH of the nutrient solution, suggests the Virginia Cooperative Extension, should be between 5 and 6 for most plants. Regular pH tests will tell you whether your nutrient solution is in good conditions.
Hydroponic systems come in two main varieties: aggregate systems and water culture systems. There are several variations on this theme. Aggregate systems use an inert material such as perlite, vermiculite, clay pebbles or sand to hold the roots of the plant being grown. Water culture systems hold the plant with the roots exposed to a stream of nutrient solution.
Lighting for a hydroponic system is required when it is kept indoors away from natural sunlight. When using a lighting system, the site must be away from any natural light to keep the natural light and the artificial lights from competing with each other. The indoor temperature should be between 55 and 70 degrees Fahrenheit and be fairly consistent. Basements are usually a good site.
The Lighting System
A two-bulb 4 foot long fluorescent fitted with standard cool white light bulbs will work for most leafy vegetables, suggests the University of New Hampshire. High lumen bulbs are available and are branded as growing lights, but are often expensive and unnecessary for growing vegetables. Flowers that require a large boost of light during the blooming season may require bulbs with higher lumens.
Adjusting the lights
A 4 foot fluorescent fixture fitted with two T8 bulbs should be hung in a space that is 2 feet by 4 feet. A light timer set for 14 to 16 hours a day will be enough for most plants. An adjustable chain that allows you to raise and lower the lights will benefit your plants growth. Three to 4 inches away from the plants is good during the growing season.