Which grow lighting is best for cannabis businesses: HPS, LED, or CMH? It's a common question among growers and it can be confusing and complicated to answer. We're doing a deep dive into each of the three main grow lighting types for cannabis businesses and which one we recommend for most, if not all cannabis growers.

What Are the Main Types of Grow Lighting?

High-Pressure Sodium (HPS) grow lights are arguably the most popular type of light for indoor growing because they produce a significant amount of light and can be found at many hardware stores. HPS bulbs tend to be the least expensive but generate a lot of heat in enclosed spaces with no ventilation, which can make them challenging for cannabis growers who don't want to use or cannot afford other types of grow lighting.

Additionally, there are some significant limitations to HPS grow lights. For one, HPS grow lights optics are designed for high ceiling warehouse operations, spreading the light at very high angles so they won't be as effective for plants grown in open spaces. If you have a more open-air concept for your grow space, you may find yourself wasting a massive amount of energy - also known as photosynthetic photon flux density (PPFD) - in light dispersion and lighting hitting the walls and aisles, not the canopy.

HPS lights also emit a significant amount of heat and will need to be monitored closely so that your indoor grow room doesn't become too hot.. Many growers know the frustration of climate-controlled growing that HPS grow lights require that with even one seemingly small mistake, it can actually kill most of your harvest yield before it fully flowers.

LED grow lights are also popular options. Some advantages of LED grow lights are that they don't emit any infrared (IR) heat for the canopy as a large difference from the HPS light output. LED light horticulture fixtures are predominantly designed to only emit light within the limits of the human eye visual spectrum. That said, LED grow lights have significant limitations in the spectrum. For example, LED grow lights don't produce UV, FR, or IR portions of the spectrum which have been shown to be important for vegetative growth and healthy flowering.

Mixed-Spectrum ceramic metal halide (CMH) grow lights are newer to the scene but they have some serious advantages over HPS and LEDs. CMHs emit an impressive array of wavelengths that include red, orange, yellow, green, blue, and violet. That's why they're sometimes referred to as full-spectrum lights. CMH grow lights also have some benefits over both LEDs and HPS - but it's important to remember that HPS has been around since 1978 (almost 40 years) and the HPS technology has essentially stayed the same spectrum over time.

One of the best ways to keep a cannabis business running smoothly is by providing healthy plants with the right amount of light. You may be wondering what kind of lighting setup you should go for: HPS, LED, or CMH? Here are some pros and cons that might help you decide which one will work best for your space.

LED VS CMH

Purchase Price
Do LED lights cost more than CMH lights? Yes! You'll spend as much as 80 per cent upfront more to buy an LED grow light than a CMH fixture.

You would have to make up about $350 per fixture in operational savings over the lifetime of the fixture to make the LEDs pay for themselves, but such savings - more, actually - are entirely likely over years of use.

Electricity Savings
Do LED grow lights help you save on energy? Yes. Spending less on energy by using LEDs instead of CMH lights comes in two ways:

LEDs give off more usable light at similar or lower wattage, saving 15 per cent on average.

LEDs emit less heat, so the cost of air conditioning, airflow and dehumidification can be lower, with results varying by location.

Longevity and Bulb Replacement
Fixtures can last a long time, so let's compare bulb replacement costs over 10 years.

CMH lighting requires frequent bulb replacements and changes:
Annual replacement of the CMH bulb, or two if you have a dual fixture.

Replacement of 4100K CMH bulbs used in the vegetative phase with 3100K CMH bulbs for flowering, then back to the original 4100K.

CMH bulbs typically are replaced every year, not because they no longer light up but because they emit significantly fewer usable PPFs after a year - probably 10 per cent less. They generally are rated to have a 20,000-hour lifespan, but at that point, their light output would have degraded perhaps 40 per cent or more - about 10 per cent a year.

LEDs are clearly the winner on replacement costs. LEDs do not require an annual replacement. These low-heat lights are considered to have a lifespan of 50,000 to 100,000 hours. If you burn LEDs 12 hours a day for a year, that's 4,380 hours. At that rate, a light that lasts 50,000 hours would function for 11 years. Because the spectrum on LEDs is adjustable, substitute bulbs for flowering aren't necessary, either.

LED vs HPS Grow Lights

While the upfront cost for LED lighting is still higher than HPS grow lights, LED grow lights cost less to operate over time thanks to reduced power consumption and the elimination of traditional maintenance. Though less costly, HPS grow lights significantly lose brilliance over time, in addition to requiring more power and maintenance. Alternately, LED grow lights don't lose intensity over time and retain their brilliance until the end of their 50,000–100,000 hour lifespan. Nevertheless, LEDs still can't quite compete with the sheer power of HPS lights.

With their minimal use of power and long lifespan, LED grow lights are quickly becoming the most efficient kind of lighting available to modern cultivars. Already implemented in some of today's most cutting-edge commercial grow operations LED grow lights combine thermal management engineering, precise spectral outputs, and advanced optics to convert nearly 100% of consumed power into targeted light energy directed at your grow.

Because of the technology that enables growers to control every nuance of their lighting, LED grow lights are able to produce great yields while consuming a fraction of the energy that their HPS counterparts use. In addition to requiring minimal maintenance, growers are often able to use just one LED grow light system at every stage of growth. This is because most LED's have been developed with spectrums optimized for the entire growth cycle. Some LED grow light designs also allow growers to adjust the emitted spectrums for the different phases of growth.

CMH VS HPS

The ceramic metal halide contains the light that is necessary for the plant to grow. On the other hand, the high-pressure sodium has a light spectrum that is good for bud. So both lights don't have advantages or disadvantages. They just contained different attributes.

All you need is to make a decision. You must think that in which section of loving you need to work more. If your plant needs more blue light, buy the ceramic metal halide. On the other hand, if your plant has an end of blue light, it needs red and orange. Buy the high-pressure sodium lights. People recommend HPS lights for many reasons. During the vegetative phase, use the HPS lights.

Using the HPS lights has a lot of advantages in the vegetative phase. These lights enhance the plant's flowering process. It also speeds up the fruiting process. One can use them in the home or for commercial use. They give a quality performance. The reliability of HPS is great. Get the details off still from the Internet. We call them powerful lights with blue light emission.

Conclusion

While the comparison is complex, LEDs have become better and more affordable lights over time, while HPS grow lights and CMH grow lights have stayed about the same in terms of efficiency and quality. While they are still primarily used in many commercial growing systems, they will likely be replaced in time by more affordable LED options in the years to come.