Setting Up Grow Lights in Hydroponics

What are grow lights?
Grow lights are lamps that mimic outdoor lighting conditions in an indoor setting. These lights emit light in the same electromagnetic spectrum or wavelength as that emitted by sunlight. Most grow lights available emit light of a particular wavelength only since plants rely on different wavelengths at different stages of growth. For example, light in the blue spectrum promotes vegetative growth while flowering and fruiting relies on the red spectrum of light.

How are grow lights used?
Grow lights have a wide range of uses, both domestically and industrially. To maximize the efficiency of the lights though, it is necessary to install reflectors as part of the lighting system. The most commonly used reflector is a PVC (polyvinyl chloride) sheet painted white on the inner side for reflective purposes and black on the outer side to prevent fungal growth. Other reflectors used are white paint containing titanium dioxide, or special reflective substances like Mylar, Astrofoil, and Foylon.
Another way to obtain maximum light is to set-up grow lights as close as possible to the plants. The disadvantage of doing so is that the plants also receive excess heat produced by the lighting system and may get damaged by it.

What are the different types of grow lights available?
Many different types of grow lights are available. The choice of lighting system will largely depend on the lighting needs of the plant itself. The preferred systems for most plants are high intensity discharge (HID) lights like metal halide (MH) and high pressure sodium (HPS) systems. Other popular lighting systems make use of incandescent, fluorescent or LED (light-emitting diode) grow lights.

Ryan Karl is an expert horticulturist who writes extensively on gardening topics. He is especially interested in all aspects of hydroponics, grow lights, or the science of soilless gardening