Last updated: April 5, 2020
Experienced cannabis growers know that choosing the right type of light at every stage of a grow operation is a critical factor in cultivating the highest quality buds with the greatest yield. While natural sunlight may be the most ideal source of light, it’s certainly not the only way to ensure a healthy crop of cannabis – and savvy light manufacturers have for years been creating ever more efficient lights for indoor plant cultivation.
Navigating the huge amount of options for indoor grow lights can be terribly confusing for anyone new to the cultivation of cannabis, though. To alleviate the frustration that can come with searching through manufacturer specifications, today we are going to take you on a guided tour of two of the most popular types of grow lights: LED, or light-emitting diode, and fluorescent lights (also known as CFLs).
By the end of the article, you’ll have all the information you need to make an informed decision on the best choice of light for your indoor grow. Let’s get started!
As far as electric light goes, LED bulbs are a relative newcomer on the scene. Because they produce light via a microchip passing electrical current into hundreds of tiny diodes, they do not “burn out” like incandescent or fluorescent bulbs; instead, their brightness will continue to depreciate over time. This means that, compared to most other lighting types, LEDs are exceptionally long-lived – making them a safer long-term investment.
Also, LED lights are equipped with a heat sink, a device that helps ensure safety and continual operation by dissipating heat energy into the surrounding environment. The combination of these technological advancements means that LEDs can be up to 90% more efficient than standard household (incandescent) bulbs, and last significantly longer.
Whereas even just a few years ago, LED lights were not nearly powerful enough for effective cannabis cultivation past the seeding stage, recent advancements such as more COBs (chips on board, referring to hundreds of tiny LEDs on one small chip) have made these lights into justified competitors at any stage of a growing operation.
LED grow lights come in three main varieties:
LEDs are the most energy-efficient style of grow lights, consuming far less electricity per lumen than fluorescent, incandescent, or HID grow lights. Especially when planning for a larger-scale grow, LED lights can provide you with more lighting per dollar spent on your electricity bill, all while being capable of producing fantastic yields and great light penetration into your grow canopy.
Along with this energy efficiency comes a drastic decrease in heat production. If your grow room tends to run hot due to the season or a lack of adequate ventilation, LEDs can provide all the necessary light for a grow without running the risk of “cooking” or burning your plants. Also, this lack of heat will reduce how often you need to water your plants, which in turn reduces the frequency with which you’ll need to add nutrients to the soil.
Lastly, because they run so much cooler, it’s also possible to place the light much closer to your plants. This means that even with somewhat underpowered LEDs, you’ll be able to achieve a significantly greater light penetration than most fluorescent bulbs. Combining all of these attributes helps to further increase the maximum potential yields during the critical flowering stage.
Because of the relative newness of LED lights, especially in the world of cannabis cultivation, it can be difficult to ensure that the LED light you are buying will be adequate for the job. Whereas standard style (“purple”) lights are widely available and affordable, many are of questionable quality – and unsuitable to the needs of even an amateur cannabis grower. For this reason, expect a significantly higher startup cost if choosing to grow with LED lights.
Aside from this, the only significant downside of LED lights is situationally specific: Because they produce so little heat, LEDs may not be a great choice for people growing in colder climates. In these cases, it’s better to have the heat of fluorescent or HID bulbs to keep the room cozy without having to spend additional money on heating the room.
Fluorescent or CFL (Compact Fluorescent Light) bulbs produce light through a somewhat complicated chemical process involving argon, mercury vapor, and a fluorescent coating or “phosphor”. In short, an electric current agitates the chemicals to produce ultraviolet light, which reacts with the fluorescent coating to produce visible light.
Why is this important? Because their light is produced by a series of reactions, CFL bulbs can take anywhere between 30 seconds and 3 minutes to display their full brightness, as explained by the fine folks over at Energy Star. Once they’re up to full light capacity, though, fluorescent lights use almost 70% less electricity than standard incandescent bulbs.
While certainly not the go-to light choice of the indoor cannabis growing crowd, fluorescent lights are inexpensive and readily available – making them ideal starter lights for the novice grower. Coming in a variety of ranges on the color spectrum, a handful of CFL lights can be sufficient for each stage of a small grow.
Fluorescent grow lights also have the advantage of being compatible with most home lighting fixtures. For the beginning grower who is just looking to understand the process, something as simple as a flexible desk lamp can be made to supply enough of the right type of light for every step of the growing cycle. Indeed, for the grower looking to cultivate one or two plants, CFL grow lights may be your best bet. One “daylight” bulb can be suitable for clones and seedlings, while one “warmer” bulb can take care of the vegetative and flowering stages.
In short, fluorescent lights are an excellent choice for first-time growers. Once you understand the growing process though, you’ll likely want to make a higher-output light one of your first purchases. Thankfully, fluorescent lights can be repurposed into home use without any difficulty.
The primary weakness of fluorescent grow lights is their relatively weak light output. Compared to other types of grow lights, you’ll need to have CFLs very close to your plants, which runs the risk of “light burn” or overheating. While you could invest in multiple fluorescent bulbs to somewhat alleviate this concern, at that point it would be a better investment to purchase a different, more powerful style of grow light.
Essentially, fluorescent lights do not have great longevity in your life as a cannabis cultivator. If they are all that you can afford to get your first grow started, then they are a natural choice! Just know that, as you continue to develop your skills as a grower, you’ll need to transition away from fluorescent bulbs fairly quickly.
LED and fluorescent grow lights both have a place in the cannabis growing world, but are definitely not equivalent. So, when choosing between the two, it comes down to two big questions:
How much experience do you have?
For the first-time grower, fluorescent lights offer an inexpensive way to get your feet wet without having to invest a huge startup cost. The tradeoff for this, of course, is not being able to grow as much bud as efficiently as you can with other lights. Think of CFLs as excellent starter lights, but ones that you’ll want to grow out of if you enjoy the growing process.
If you’re an experienced grower, LED grow lights offer a step up from more traditional lighting sources – especially the COB style, which most closely mimics sunlight. So, when you’re confident that you can take good care of your plants and are ready to make more of an investment in producing a larger yield, choose LED grow lights over fluorescents.
How much of a startup cost can you afford?
The major difference in LED and fluorescent grow lights is absolutely the startup cost. Whereas you can go to any hardware store and walk out with two fluorescent bulbs for around $20, a high-quality LED light designed for cannabis cultivation can set you back hundreds of dollars… At least initially.
However, if you’re in it for the long haul: Choose LED lights.
What you pay extra for in startup cost, you can easily recoup through reduced electric bills and the bulbs’ greatly increased life span as compared to other lighting choices. To summarize: LED grow lights are more cost-efficient as time goes on, while fluorescents are a cheaper way to get started.
Whether you’re just planning your first grow, or are a seasoned veteran, choosing the right light source for your indoor cannabis cultivation can make the difference between a lush bounty of bud, or weak and struggling plants. We strongly recommend considering what your budget is for your grow and choosing the best light that you can afford – it really is that critical to your success! Just remember: What you pay for in upfront costs, you will almost definitely recover in energy efficiency and overall production of high-quality flowers.
Featured Image Credit: NASA Marshall Space Flight Center, Wikimedia Commons
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