420 Grow Lights for Cannabis

High-Intensity Discharge (HID) Plant Grow Lights

High Intensity Discharge (HID) Plant Grow Lights High Intensity Discharge (HID) lamps in metal halide (MH) and high pressure sodium (HPS)

have shown themselves to be particularly suited for growing large plants indoors. Initially these lamps were utilized for horticultural purposes as supplemental greenhouse lighting, allowing commercial growers to add lighting to their crops on cloudy days or extend the day length during the winter months.

Full size HID plant growing lights

are comprised of a remote ballast, a reflector for directing light down to the plants, and a lamp cord that connects the ballast to the reflector and incorporates the mogul socket that holds the bulb. Historically, HID lamps were constructed with a classic magnetic core and coil transformer, but now new electronic versions are commercially available that allow dimmability, weigh much less than standard ballasts, as well as offering other advantages.

Metal Halide (MH)

is a highly efficient light source capable of delivering a white light in the range of 2700 to 5500 Kelvin degrees with a typical Color Rendering Index (CRI) ratings in the mid-60's to mid-70's. Some lamp chemistries even obtain CRI's in the 80s. The CRI is an index that measures how closely an artificial light source matches the natural colors of sunlight, with 100 being a perfect score. In contrast, high pressure sodium lamps (below) yield yellow lighting (2200K) and have a very poor color rendering index of 22. By varying the blend of chemicals in the arc tube, metal halide engineers are able to alter the characteristics of the light output. This flexibility in design is what makes metal halides so versatile. White light is a very important attribute of metal halide technology, because it is the closest to the natural sunlight that people prefer.

Metal halide lamps

are widely used where color rendering is important such as stadiums, malls, manufacturing plants, and supermarkets. For horticultural purposes, metal halides tend to produce a shorter, more compact plant habit that more closely resembles plants grown outdoors. A plants appearance growing under most metal halide lamps is almost identical to those growing outside, which makes it the preferred lamp for use in living areas. Horticultural metal halide lamps have an enhanced red spectrum, hardly noticeable to the naked eye, which is added for improved fruiting and flowering without sacrificing plant appearance. Metal halide lamps are about five times more efficient than their incandescent counterparts and last up to 25 times longer, with a usable lifespan between 10,000 and 20,000 hours, depending on the wattage.

High Pressure Sodium (HPS) lamps

have been used for years in less color critical applications such as parking lots, street lights and as supplemental greenhouse lighting. The benefit of high pressure sodium lamps to the horticultural industry is their ability to enhance the fruiting and flowering process in plants. The orange/red spectrum HPS produces is the spectrum plants use in their reproductive processes, which generally produces larger harvests of higher quality fruits or flowers.