Many indoor gardeners switch to sodium lamps when it is time to induce flowering or fruiting of their plants. HOOD The reflective cover used in conjunction with an HID lamp. The more reflectivity a hood can provide, the more effective it is. An industry code indicating that the bulb is to be operated in a horizontal position. The area immediately under an HID lamp where the light intensity is strongest.
Hot spots cause uneven growth, but can be remedied by using light movers.
The act of illuminating or state of being illuminated. This term is often used incorrectly in place of the term illuminance to denote the density of luminous flux on a surface. Incandescent lamps are the most familiar type of light source, with countless application in homes, stores and other commercial settings. Light is produced by passing electric current through a thin wire filament, usually a tungsten. They also put off far too much heat per watt to use in horticulture, even if the above-mentioned problems did not exist.