Grow lights are used in a variety of indoor growing environments, including greenhouses and spaces used for hydroponics gardening. Hydroponic gardening is the growth of plants without the use of soil. Instead, plants get their food from a nutrient solution. Grow lights make it possible to grow hydroponics indoors.
Grow lights provide the proper wavelength, or color light, for plants to grow. This is also called the quality of the light. Sunlight provides the entire spectrum of light needed for a plant to grow. Blue and red light are the two light qualities that plants absorb to grow. Blue light makes vegetation grow, such as leaves, and red light along with blue light makes plants grow fruit, flowers and vegetables.
Meta halide and HPS
Meta halide can be used during the initial growth and propagating phases of growing a plant. These produce blue-white light, which is good for leafy growth. High Pressure Sodium bulbs, or HPS bulbs, are the best for the final flowering stages as they produce red-blue light. Conversion bulbs of each type can be purchased to use in the other bulbs system, so that the lighting system does not have to be changed for each bulb.
LED lights can be used to grow hydroponic plants as well. LED lights consume less power than HPS and meta halide bulbs. LED lights only use the spectrums of light required for plant growth, meaning that no energy is wasted. LED UFO lights provide the light required for all cycles of a plants life.
Electronic ballasts can be used to run the lights in your hydroponic growing environment using a computer software program, turning on lights as they are needed during the growing cycle. Electronic ballasts can be used with HPS and meta halide bulbs, having connections for both. These ballasts save energy by adjusting output according to which bulbs are being used.
Light placement and size
Light can be used to emulate the cycle of a normal days sunlight. Plants need 50 to 80 watts of light energy per square foot of growing space. The number of hours of light needed depends on the plant itself, whether it is a cool or hot weather plant, and whether it produces fruit or flowers. Meta halide and HPS bulbs need to be placed at least 12 to 18 inches away from the top of the plants to keep them from burning.
Lighting affects the nutrient solution in your hydroponic system by dehydrating it and causing nutrients to concentrate in the solution. If you are using grow bulbs, it is important to regularly check the pH of the nutrient solution, and change it every two weeks.