Let’s cut through the misinformation and get the facts on which light is best for you.
Ok, so you’ve probably read other opinions on the LED vs HPS grow light debate. It’s a contentious issue with marijuana growers lining up on one side or the other to fight for their cause. Does that mean you will never get the straight dope on which lights to choose? Absolutely not, I’ve got you covered right here.
Quick recommendations before we get into detail:
HPS – High Pressure Sodium HID (High Intensity Discharge). Best for professionals, experienced growers, bigger budget grows, and vertical grows. The primary downside to HPS is the heat they produce.
LED – Light-emitting diode. LED quality varies widely. If the best brands and models are chosen, they will be the right choice for new growers, growers on budget, stealth growing, and low maintenance growing. LED lights excel at efficiency and lower heat levels compared with HPS. LED lights allow for light wavelength selection and customization. By tuning LED to the light frequencies plants respond to best, LED lights can deliver more yield with less wattage used.
MH – Metal Halide. MH lights are typically used as veg lights before plants are moved under HPS for flowering. MH for vegetation growth, HPS for flowering is a great setup for large scale operations.
CFL – Compact Florescent Lights. CFL lights are remarkable efficient lights that still have a place with all levels of grower. CFL’s are a favorite for germination stages and cloning. CFL’s can also be used for the smallest grow rooms, closets, and stealth growing. CFL’s produce vary little heat and are still a viable choice for small scale or beginning growers from start to finish.
If you are a new grower, growing small amounts, short on space (closet grow), on a limited budget, or concerned about stealth growing – LED is probably the best choice for you. See below for brand and model recommendations. LED grow lights vary widely in quality.
If you are a seasoned grower that is looking to commit space and resources to producing higher yields, HPS is probably your best fit.
Why is LED best for new / small / budget grows?
Mainly because of the heat generated by HPS. Most growers will agree that HPS lights are capable of producing high quality yields. Award winning cannabis is often grown under HPS. The heat produced by HPS can be dangerous and difficult for new growers to handle. HPS light require extra space and/or special considerations to account for the heat generated.
LED is relatively new technology for grow lights and has made huge improvements over the last couple years. It’s reasonable to conclude that LED will continue to improve and is likely to be the superior light for almost all applications in the future. As of today – July, 2017 – LED is not the best choice for all growers. That may change in the coming years as LED technology becomes more efficient by targeting the most beneficial wavelengths of light.
Besides efficiency, LED lights are often more flexible for growers. HPS lights usually require separate spaces for veg & bloom, or the lights must be changed within the same space. Many LED lights now offer a simple switch that changes frequencies for veg or bloom.
What about vertical grow spaces?
HPS is the best choice for vertical grow rooms. By hanging a bulb vertically, HPS lights become significantly more efficient. 360° of unobstructed light being absorbed on all sides by plants. The increased efficiency means that a cool tube (enclosure for super hot bulbs) becomes a wise choice for safety and to decrease the time involved in positioning plants near an HPS bulb that is unprotected. A tube surrounding an HPS will decrease efficiency by around 10%. Using 360° more than offsets that small decrease in efficiency.
Vertical growing + HPS lights can be a viable choice for small grow areas. Small-ish. LED and CFL are still going to produce much less heat and offer the safest and easiest options for small space growers.