High-Intensity Discharge (HID) lighting refers to powerful lamps—primarily Metal Halide (MH) and High-Pressure Sodium (HPS)—that have been widely used in indoor cannabis cultivation. MH bulbs produce a blue-white spectrum ideal for vegetative growth, while HPS lamps emit red-orange light suited for flowering.
HID systems are energy-intensive but provide strong light penetration, making them effective for dense canopies.
Modern alternatives such as LEDs are increasingly replacing HID due to greater efficiency.
