Grow lights use three major types of lighting, namely the incandescent, fluorescent and high intensity discharge or HID.Grow lights are an electric lamp designed to compensate for the sunlight requirements of plants which are planted indoors. This lighting system works by transmitting an electromagnetic spectrum applicable for photosynthesis. The diffused light spectrum resembles that of the sun to allow the indoor growth with outdoor conditions. The natural daylight appears to be bluish and has high color temperature of about 6000K. Grow lights use three major types of lighting, namely the incandescent, fluorescent and high intensity discharge or HID. The incandescent lights have a low color temperature, which is about 2700 K. their color tone is red-yellowish. Incandescent lights are used to highlight indoor plant groupings, rather than as a true plant ‘growing’ light because they are less energy-efficient and convert much of the electricity into heat instead of light. They also have a life span of 750 hours. Fluorescent lights have several advantages over the incandescent. Indoor growers used the fluorescent lights until the early 1980s. Their color temperature ranges from 2800 K to 6000K. The light they emit is three times as much as the incandescent lights. Also, their light spectrum is appropriate for plant growth. They are particularly helpful in cloning and starting seedlings. Moreover, fluorescent grow lights discharge less heat while providing more gentle light than the HID lamps. Its distinction of releasing lesser heat is of advantage to indoor growers in not well-ventilated spaces. However, on the other side, the light emitted by fluorescent tubes is not concentrated on one area. Instead, the tubes illuminate a large area, and thus, they must be suspended very close to the plants, about 2 inches from the grow tips. They should also be transferred constantly to promote plant growth, making garden maintenance rather laborious. The best type of fluorescent tube is the ‘cool white’. The other varieties including grow-lux and vitalite do nothing for plants. Indoor growers who use cool white fluorescents confessed that they have optimal results by mixing warm-white lamps in a fluorescent mixture. The High Intensity Discharge grow light are more efficient and easier to use. HID lights that have low wattage are used for household outdoor use while the high wattages are used to light the streets, parking lots, stadiums and similar large areas. HID light come in two varieties: the Metal Halide and the High Pressure Sodium. The Metal Halide can deliver white illumination in the range of 2700 to 5500 K. For plant growth, the Metal Halide HID produces a shorter and more compact plant habitat that resembles more closely the growing outdoor conditions. The plant’s appearance grown indoors with Metal Halide is not different from the plant’s appearance grown outdoors. The High Pressure Sodium, on the other hand, provides yellow lighting of up to 2200K color temperature. Its color rendering index, however, is very poor at 22. The Color Rendering Index or CRI is an index measuring how close an artificial light source can match the natural colors of sunlight, with 100 as the perfect rating. The High Pressure Sodium lights are used for the second phase of plant growth. If they are used for vegetative phase, the plants will have quicker growth. Its drawback, when used as grow light is the high tendency of the plant to grow taller and leggier compared to plants grown with Metal Halide. Choosing the ideal light for your plants can be done by considering where and how the plants grow best in their natural habitat. Most vegetables thrive best in full sunlight, while foliage plants grow in full shade. Other Popular Posts: ________________________________________________________________ Page listed under Hydroponics Gardening |