can you grow marijuana with led lights

Using LED Grow Lights: 6 Mistakes to Avoid?

Whether you are new to growing cannabis or just new to growing with LEDs, mistakes can happen! Find out what you should avoid in order to grow top-tier cannabis under LED lights!


Growing great cannabis is not really difficult—at least in theory. Get yourself some quality cannabis seeds, good soil, proper containers, and you’re already off to a good start. However, if there’s one factor that’s especially crucial to developing superb cannabis, it’s light—a lot of it. Indeed, cannabis plants require more light than most other plants, and they optimise performance if light exposure is significant and consistent. As such, you really don’t want to skimp when it comes to your grow lights.

In the past, weed cultivators largely used HID lights—with MH (metal halide) lights used for vegging and HPS (high pressure sodium) lights employed for flowering. HID lights are still viable, and they have a great track record amongst home and commercial growers alike. That said, LEDs are exponentially taking over grow rooms around the world. Why? Compared to HID, LEDs have some convincing advantages: They use (a lot) less electricity, allowing you to save money over time and reduce the footprint you leave on the environment. They also emit less heat, which can be a big advantage, especially in small grow setups. Lastly, LEDs have recently become more affordable as the tech has become widespread, allowing home growers an opportunity to benefit from this unique and powerful lighting system.

Yet, even the fanciest LED lights cannot prevent growers from making mistakes in their grow. Let’s delve into some common errors, slips, and faux pas to avoid when growing cannabis with LEDs.


This is probably the most common mistake that inexperienced growers make upon just starting out with LEDs. Since HID lights emit a lot of heat, out-of-the-loop growers might be overly cautious with their LEDs, placing them too far away; alternatively, those aware of the benefits of LEDs might get cocky and place the lights super close. If you hang your LEDs too far away, there’s a good chance your plants will over-stretch in an effort to reach closer to the light. If, on the other hand, you place your LEDs too close to your cannabis plants, this can stress the plants more than they can comfortably handle, causing burning and bleaching of the foliage and buds.

So, what is the ideal distance between your grow lights and your plant canopy? Unfortunately, there is no standard, since the best distance during the vegetative and bloom phases of your cannabis will depend on your specific LED. Each type can vary slightly, therefore affecting the final distance they should be from your plants. The first port of call is to check the manual you received with your LEDs for any information on recommended distance. If you can’t find it there, check out the manufacturer’s website. If, for whatever reason, you cannot find any information, you can keep your LEDs somewhere between 30–45cm from the canopy—around 45cm during veg, then a little closer when your plants are flowering.

When adjusting the height of your LEDs for peak performance, keep an eye out for any oddities. Dry, curled, brown, or bleached leaves signal too much light, calling for your LEDs to be raised higher.


Because good ol’ HID lights emit a lot more heat than LEDs, soil normally dries out quicker when utilising the former. Once growers make the switch, however, they often forget to take this into account. Given the significant reduction in heat, it’s likely your plants will need less frequent watering. So adjust your schedule accordingly when using LEDs, especially if you’re new to it. Overwatering is a common and sometimes serious error beginners make that paves the way for a host of pests and diseases to take hold. So this is really important to keep an eye out for. When in doubt, let your soil dry out—then you can water again.


Most LED grow lights you can find today are “full spectrum” lights, which is sort of a buzzword that means you can use them for vegging and flowering. But there are also models outfitted with a switch that allows you to change the light spectrum according to the phase. Moreover, some LEDs are made only for veg—emitting a bluish light that supports fast and vigorous growth—while others are made for bloom, giving off a reddish light to support bud development. So, before you get an LED light, make sure it’s the right type. For most growers, a full spectrum LED is likely what you’ll want.


If there’s one drawback to LED lights in comparison to HID, it’s that a quality LED is significantly more expensive outright . Not everyone has the cash upfront for a high-quality, full spectrum LED, so they look for ways to save money while still benefitting from the technology. The problem is, there are now tons of low-quality LEDs available on the internet to satisfy this very issue—and these manufacturers are not prioritising quality. These cheap LED lights are often manufactured overseas, and claim to provide more light than they’re actually capable of. Some of these lights are only able to grow one plant (if you’re lucky), and not much more. Low-quality LEDs can also be dangerous to operate if they’re made in a country that has less strict requirements on electrical safety.

Lastly, if you get a cheap LED from overseas and you run into trouble, you will likely have a hard time with warranties and returns. As almost nothing is as important as your lights when growing cannabis indoors, it’s simply not smart to cut corners here. By spending a bit more on a quality LED, you and your plants will be so much happier. Plus, high-quality LEDs are much less expensive to run than HIDs, so you’ll surely save some serious cash on your energy bill over time!


The issue with many of those cheap “beginner LEDs” is that some manufacturers intentionally confuse the grower with specs and numbers, such as wattage. This seems fine, except that, with LED lights, wattage doesn’t really say how much light the LED is emitting; it says how much energy is required to produce the light. Instead, we’re measuring in lumens—the amount of light actually emitted. So, regardless of how high the wattage is, the light could still have a poor spread and/or doesn’t penetrate the canopy well. In other words, don’t fall victim to misleading information, and consider the source of your product.

Providing your plants with enough light can become an issue if you want to grow more than one. For example, one single 300W LED light fixture may be fine for one or maybe two plants, but it may not be enough to cover a bigger space with multiple plants. So make sure to reference any recommendations from the vendor and/or LED manufacturer on how much light you will need for your growing space. You can also look for reviews and user reports on grow forums if you want to know more about using a particular LED.


At most high-quality seed shops, you can get autoflowering cannabis seeds and feminized photoperiod cannabis seeds. Autoflowering strains are relatively easy to grow, especially when it comes to lighting: You can just keep them under an 18–24-hour daily light schedule from the moment you plant your seeds up until harvest. They flower automatically after a few weeks of growth, which makes them very convenient.

Feminized (photoperiod) strains, on the other hand, are typically grown under 18–24 hours of light in the vegetative stage, then under 12 hours of light and 12 hours of darkness to initiate and sustain flowering. This shouldn’t be a problem, as most growers will set their lights on a timer for this very purpose. Then again, for someone who’s just starting out, they might not feel confident tailoring different light cycles and spectrums, especially if their setup doesn’t utilise full spectrum lights. It’s certainly not impossible for beginner growers to swiftly get the hang of maintaining proper light schedules, but sometimes the new tech of LEDs can lead people to make silly mistakes. In that case, you may wonder why your plant is reaching gigantic heights, but won’t grow you any buds!


For more tips on growing with LEDs, check out our blog on how to make the most of your LEDs. Lastly, keep in mind that even the most advanced LED system doesn’t just magically grow good weed. So always be sure to provide your plants with the necessary water, nutrients, substrate, and all the other great things it needs. With patience, care, and some powerful LEDs, your plants will reward you with fat, resinous buds come harvest!

LED lights have become increasingly popular in the cannabis grow community. If you plan to grow weed under LED lights, avoid making these 6 common mistakes!

Can you grow marijuana with LED grow lights?

Please note: This article was written in April 2012. Since then, LED grow lights have been improved to produce even better results when growing marijuana.

You may or may not know about the LED grow light craze for marijuana growers.

LED grow lights use less energy and generate much less heat than standard HID grow lights, so there’s good reason for all the attention.

The Truth About LED Grow Lights
by Nebula Haze and endive

Today, I’ll be answering the following questions:

  1. Why is there so much controversy about whether LED grow lights even work?
  2. Which companies, if any, have the best LED grow lights (specifically for growing marijuana)?

Some people say LEDs work great for growing marijuana, while others claim LED grow lights are junk and can’t be used to grow anything.

The truth is that both sides are right.

Now, I’m talking about grow lights made of light emitting diodes, commonly known as LEDs. You may have seen ads for these lights, which often resemble UFOs, and claim to be the growing technology of the future.

First invented in 1927, no one could find any practical use for these tiny lights until 1962, when LEDs first hit the scene in 1962 as glowing red indicators on electronics.

After that, LED development has proceeded rapidly.

LEDs, which were originally tiny and dim, have doubled in efficiency and light output about once every 36 months since the 1960s.

As you probably know, humans have tried growing plants with just about every type of artificial light we’ve ever created, and LEDs are no exception.

Which has all led to the development of LED grow lights.

At first, no one could successfully grow anything using LEDs. Each individual LED is relatively small and produces only a specific wavelength(color) of light, and we couldn’t seem to successfully replicate the proper strength and color of sunlight.

But through trial and error, we’ve now developed some wickedly effective LED grow lights.

And LED grow light systems have some pretty sweet benefits:

  • Extremely efficient and uses a fraction of the electricity of other grow lights
  • LED light systems run extremely cool and most do not need you to do anything to control heat
  • Most LED light systems can be plugged directly into a regular power outlet, and don’t need a ballast or special light socket like most other grow lights.
  • Some growers claims that marijuana buds grown under LEDs contain more THC and other cannabinoids (which may be because marijuana produces stronger buds when slightly stressed)

Now, it’s a proven fact that LEDs can be used to grow plants from the beginning to the end of their life cycle.

I know this is true because I have personally have grown marijuana plants from seed to harvest with a Lighthouse Hydro BlackStar 135 Watt LED grow light system.

My search for LEDs started because I live in an area where heat can be an issue. I am also a small scale grower who would like to still have a presentable house for guests.

Where I was living at the time, I didn’t want to have install ducting for ventilation or anything like that, which made HID lights pretty much out of the question for me.

Based on the experiences of some of my fellow growers, I discovered many LED grow light systems just don’t work for growing marijuana.

After doing some research, I got my Lighthouse Hydro BlackStar 135 Watt LED grow light in 2012. I got a second one a few months later, I’ve grown 3 crops in total under just these BlackStar panels, growing two small plants under each UFO LED Grow Light panel.

My yields under the Lighthouse Hydro Blackstar were a bit smaller than normal and throughout the grow my plant leaves appeared a bit beat up (got occasional spots, brown marks, and other signs of light stress, especially the leaves close to the LEDS), but the buds produced with the Lighthouse Hydro Blackstar were always dank, ultra-poten and sticky.

The incredible quality of the buds kept me trying to find ways to up the total yields.

Plus I was saving money on my electricity bill (electricity use with the Lighthouse Hydro Blackstar LED Grow Light was minimal), and there was no heat to speak of, which really simplified the heat situation in my tiny, tiny closet.

I was pretty satisfied with the results.

Then I had the pleasure of running into other growers who have used specific models of LED grow lights that work FANTASTIC.

So LED grow lights can work, but at the same time, it is true that some work much better than others. And there really are dishonest companies out there who probably just slapped together a bunch of LEDs, which no consideration to what’s really needed to grow a plant, and these LED grow lights will never grow anything, no matter what you do.

In today’s article, it is my goal to share with you 2 brands of LED Grow Light that have been proven to work great for growing marijuana, so you can skip the trial and error.

Lighthouse Hydro BlackStar 135W LED Grow Light
(3W Chipset)

Verdict: Great for the small-scale grower who wants to grow 1-2 plants in a closet

Price: About $180

Pros: Low heat, low electricity use, 1 year warranty, incredible quality of buds produced (seriously the potency is 10/10), can grow two plants with one Hydro Blackstar panel

Cons: Smaller-than-average yields, someone airy buds, leaves closer than 15″ to the light can show signs of light stress.

Here are some pictures of the plants which were grown primarily under the Hydro Blackstar panel. The top three show the plants a month before harvest, and the bottom two photos are from the day of the harvest. The purple pictures show what the buds look like under the LED lights. Click on any of the thumbnails to see a bigger version!

Close-up of the trichromes on one the buds growing under the
135W Blackstar LED Grow Light Panel (3W chipset)

Pro-Grow 400

Learn more about the Pro-Grow 400

Verdict: Great for the discrete small to mid-sized grows (4-6 plants) in a closet or grow tent. “This is a solid LED grow light that will give a 600 watt high pressure sodium system a fair run… but at half the power consumption.”

Price: $550 (for one of these efficient monsters)

Pros Will outproduce a 400W HPS using only 240 watts of electricity, very little heat produced, and buds are “Potent enough to catch even experienced patients off guard, to the point that the batches out in the local Med community have been nicknamed ‘Warning Label.'”

Cons: Expensive initial investment

The following information and pictures are here thanks to endive from Definitely check out his website out for tons more pictures and to get updates about their current and future medical marijuana grows!

The Pro-Grow 400 easily covers a 4′ x 4′ area, and up to 5′ x 5′ with a little plant rotation & shuffling.

Ideal setup for a grow tent or closet is to have the taller, lanky plants toward the edges of your grow area with the shorter and denser plants located center, directly under the lamp. You may even raise the ‘edge’ plants up a bit so they are closer in height to the LEDs.

Keep Pro-Grow about 20″ above plants. The days of having to keep your LED grow lights just inches above your plants are over.

Suggested Strains that have worked beautifully with the Pro-Grow 400 (with pics to prove it… click for closeups!)

Nirvana Aurora Indica: An F1 hybrid of Afghan and Northern Light. Its plants stay short, producing heavy colas and dense buds. This marijuana strain produces exceptional amounts of resin, resulting in a deep, near-black hash with a tasty aroma and a heavy buzz. This probably is Nirvana’s most potent Indica seeds strain.

Blackberry: Quickly gains mass, trichomes & aromas! Fast growing, dense colas from top to bottom, trichome coated & smelling of ripe fruit and jet fuel.

Northern Lights: Quick to flower, high producing. Aromas vary from ‘incense & hashish’ to ‘honey & tangerine’, but they were all sweet & herbal on the inhale, gentle on the lungs as the spicy/incense undertones become more prevalent. You’d wish you could hold it in forever, as you reluctantly exhale, you are rewarded with one last aromatic blast of sandalwood and hashish…

Jock Horror: Jock Horror produces so much resin that even its branches glisten with THC glands. This marijuana strain’s variety has a unique fresh flavour and packs a strong “up” buzz. Buds look dank! While manicuring the freshly cut colas, I found myself having to change out or clean my scissors & shears every few branches. They are the stickiest Jock I’ve grown to date yet and by far the most delicious smelling, almost a melding of skunk & cotton candy!

I hope you enjoyed today’s article all about LED grow lights for our favorite herb, marijuana!

About endive from

“I try to show the average guy or gal how they can free themselves from the grips of dealers and dispensaries. Hopefully this will empower other patients to do the same, and that makes it all worth it.”

I hope that helps you as much as it would have helped me when I first looked into growing weed with LED lights!

If you haven’t started growing marijuana yet, today is the day! Learn the basics.

LED grow lights use way less electricity than regular grow lights and barely produce any heat. But do they actually work for growing weed?