5 Best LED Grow Lights 2021 (Yields, Speed, & Bud Quality)

Published May 30, 2021

by Nebula Haze

LEDs have overtaken HPS and other HIDs as the best cannabis grow light for nearly all home growers. Although there are some situations where LECs or HPS are a great choice (for example in a cold space where the heat of the lights is a positive thing, or if you’re making concentrates and want to use special bulbs to increase trichome production and terpene levels/smells), generally most home growers will be happiest with LEDs.

LEDs grow magnificent cannabis plants indoors without much heat or electricity. Today you’ll learn about some of the best LED grow lights for cannabis plants.

HLG 300 LED Grow Light being used to grow 8 cannabis plants in the vegetative stage in a 3'x3' grow tent

Why LED Grow Lights?

  • More light, less heat – LEDs produce more light and less heat than HIDs, watt-for-watt
  • Better for heat control – Not only do LEDs run cooler, plants under LEDs actually prefer warmer temperatures. That means they are the perfect grow light to deal with heat. If your grow space is room temperature or warmer, LEDs are your best grow light choice when it comes to controlling heat.
  • More colorful buds – LEDs tend to bring out colors like pink and purple on buds and leaves. Although some strains will stay green no matter what, many strains have the ability to turn color in certain environmental conditions. LEDs will almost always bring out colors in those strains especially as plants approach harvest.
  • Excellent bud yields & potency – In my side-by-side grows using clones, modern LEDs produce similar or higher yields, better bud quality, and even significantly more THC than comparable grow lights like HPS and LECs.

I’ve been testing LEDs on cannabis plants for over a decade, and most of those LEDs produced subpar results as far as yields, speed of growth, and bud quality. However, around 2018 the newest models of LEDs started matching and even beating the results I was getting from HPS and LEC grow lights. The rate of improvement on new LEDs seems to be speeding up since then, not slowing down. It may come as a shock to us old-timers who were underwhelmed by older LED technology, but new LEDs have fairly won the title of “best cannabis grow light” for home growers in my opinion. Today I’m going to share some of the best LED grow lights for cannabis so you can harness that power in your own grow.

The Electric Sky ES300 produces dense heavy buds. This is Version 3, which produces even brighter light than the previous versions.

 

5 Best LED Grow Lights for Cannabis Plants

Some LEDs are far better than others for growing cannabis, and the “best” LEDs change every year. Since I used my first LED grow light in 2008, the top LEDs companies have changed drastically. Many of the old popular LED companies aren’t even around anymore, while new companies are appearing daily.

For example, ViparSpectra used to offer competitive LEDs at great prices, but they have not updated their lights to keep up with current technology. Their current models perform consistently worse than many other LEDs in my tests when it comes to speed of plant growth, yields, and bud quality. So although we used to recommend ViparSpectra models as a budget LED light, they’ve fallen off the list to be replaced with LEDs that use more modern technology. The new recommended budget light, the Spider Farmer, has been astounding in its quality. It offers many of the features and similar results as much more expensive LEDs.

For me, 2021 is the most exciting year yet when it comes to LEDs. The choices are better than ever as more and more people figure out ways to tweak LEDs to produce even more yields and better cannabis bud quality.

Today, the best LED grow lights for cannabis obliterate the results of the worst LED grow lights. The challenge for the grower is figuring out which models to avoid and which LEDs work the best. After tests with real cannabis plants, we’ve narrowed down the list to our 5 best LED grow lights for growing weed in 2021.

  1. Spider Farmer (Best Budget Light)
  2. Electric Sky (Best Yields)
  3. HLG Quantum Board (Best All-Around)
  4. Mars Hydro (Best Coverage)
  5. Custom LED Mix (Most Modular)

 


 

1.) Spider Farmer (Best Budget Light)

Spider Farmer is a sleeper. If you’re not sure which grow light to get and cost is an issue, get one of these lights. They’re not perfect but are well constructed, don’t need any setup, are easy to use, fast plant growth, and get surprisingly great yields for a small amount of electricity. I was impressed with these lights even after using more expensive LED models.

My current grow featuring the Spider Farmer SF-2000 (buds are amazingly fat at just day 28 of flowering)

Spider Farmer SF-1000

  • Price: $160
  • Grow Space: Perfect for a 2’x2′ grow tent or closet
  • Actual Power Consumption: 100W at full power, and can be dimmed. This light uses the least electricity on this list but still produces hefty buds.
  • How Far to Keep from Plants: 18″ for the vegetative stage. 12-18″ away in the flowering stage (keep as close as 12″ away but if top leaves appear pale from light stress, move to 18″ away)
  • Average Yields: 2-5 oz+ – keep in mind that the strain (genetics) and any plant training you do will make a huge difference in your final yields.

Chasb40 had this to say about the SF-1000: “Loving the light, plants are as well. Solid build and I don’t have to worry about hot temps in my tent, much cooler than the older blurple LEDs…and quieter.”

 

Spider Farmer SF-2000

  • Price: $260
  • Grow Space: Perfect for a 2’x4′ grow tent or closet
  • Actual Power Consumption: 200W at full power, and can be dimmed for younger plants. This light uses less electricity than any other LED on this list besides the SF-1000, but you wouldn’t be able to tell with the results you get. Its low power consumption is another reason this is a great budget grow light.
  • How Far to Keep from Plants: 20-24″ for the vegetative stage. 18-24″ away in the flowering stage (keep as close as 18″ away but if top leaves appear pale from light stress, move to 24″ away)
  • Average Yields: 4-10 oz+ – keep in mind that the strain (genetics) and any plant training you do will make a huge difference in your final yields.

David grew this plant with a SF-2000 and reported back, “Great lights. They don’t get very hot. Super light weight. Produce great buds. 100% recommend!”

Janelle’s results on her first cannabis grow (three SF-2000s in a 5’x5′ grow tent)

Spider Farmer SF-4000

  • Price: $560
  • Grow Space: Perfect for a 5’x5′ grow tent or space
  • Actual Power Consumption: 450W at full power, and can be dimmed.
    • Note: No front-facing dimmer. You have to unscrew the driver from the board and then you’ll see the dimmer.
  • How Far to Keep from Plants: 24″ for the vegetative stage. 18-24″ away in the flowering stage (keep as close as 18″ away but if top leaves appear pale from light stress, move to 24″ away)
  • Average Yields: 9-20 oz+ – keep in mind that the strain (genetics) and any plant training you do will make a huge difference in your final yields.
    • Note: the SF-4000 light can get quite hot compared to the other Spider Farmer LEDs. Unless growing in a particularly cold grow space, you will probably need an exhaust fan or AC to control the heat from this light. Keep the temperature between 75-85°F (24-30°C) to get the best yields.

“Very nice little 450w lights indeed! My buddy’s little medical garden did very well and produced very high quality medicine. 1.91grams per watt, organic notill beds. Strains were, blackberry Kush, GG4, 501st OG, and a special cultivar called Pineapple Dreamwreck.” ~Robert

 


 

2.) Electric Sky (Best Yields)

Features of the Electric Sky LED grow lights

  • Outstanding yields with long, dense buds
  • Excellent bud potency and quality
  • Fast vegetative and flowering growth (some LEDs perform great in flowering but have sluggish growth in vegetative – this brand produces great growth speed in both stages)
  • This is my absolute favorite LED grow light for cannabis. However, I didn’t name it the “best all-around” for two reasons: 1.) the price tag is significantly higher than other options on this list, and 2.) the lamps are surprisingly big and weighty. I like sturdy construction but these LEDs are bulky, heavy, and annoying to hang up. If you don’t care about those two downsides, I think this is the best LED grow light for cannabis on this list.

This older version of the Electric Sky 300 produced over 11 oz of buds from 3 plants

Electric Sky ES300

  • Price: $695
  • Grow Space: Perfect for a 2’x4′ grow tent or closet
  • Actual Power Consumption: 300W at full power, and can be dimmed for younger plants
  • How Far to Keep from Plants: 20-24″ for the vegetative stage. 18-24″ away in the flowering stage (keep as close as 18″ away but if top leaves appear pale from light stress, move to 24″ away)
  • Average Yields: 9-11 oz+ – keep in mind that the strain (genetics) and any plant training you do will make a huge difference in your final yields.

Electric Sky 300 LED grow light (ES300)

ES300 LED grow light showing off its unique spectrum

I did a side-by-side grow journal with the Electric Sky ES300 and it performed beautifully in both coco and soil with an average of over 10 oz per ES300. The bud quality was also outstanding.

Peyote Critical grown under the ES300

We grew these under two ES300s in a 4’x4′ grow tent

Six flowering plants in a 4'x4'x6.5' grow tent under 2 x Electric Sky 300 LED grow lights - 34 days of flowering

Pineapple Chunk bud from the above grow

 


 

3.) HLG Quantum Board (Best All-Around)

Horticulture Lighting Company (HLG) took the world by storm with its line of “quantum boards”. This style LED grow light was developed by hobbyist LED growers and HLG made it available commercially and turned it into a phenomenon. Now many grow lights have very similar form factors, but HLG models are still some of the best-performing. These lights are tested on real cannabis plants, and HLG releases an updated version on a regular basis as new technology is discovered and developed. However, companies like Spider Farmer are starting to offer “copycat” versions of HLG lights that seem to be performing just as well for less money. I’m not sure HLG will be able to hold this spot next year.

Why was HLG the Best All-Around LED grow light company on this list?

  • Great yields (but not quite as good as Electric Sky in my experience)
  • Excellent bud quality/appearance
  • High bud potency (in some tests, the buds grown under HLG lights produced significantly higher levels of THC than HID grow lights like LECs)
  • Lightweight and easy to set up

These Mandarin Cookies buds grown under the HLG 300 measured 28.3% THC at the lab. Buds from a clone of the same plant grown under a LEC only measured 26.94% THC at the lab. We found increased potency across the board when we lab tested clones grown under HLG vs LEC grow lights. HLG LEDs seem to help maximize the potency of buds.

HLG 300L Quantum Board (R-Spec version recommended)

  • Price: $400
  • Grow Space: The rectangular shape actually makes this model perfect for a 2’x4′ grow tent or closet.
  • Actual Power Consumption: 270W at full power, and can be dimmed down to 90W for younger plants
  • How Far to Keep from Plants: 20-28″ for the vegetative stage. 18-24″ away in the flowering stage.
  • Average Yields: 8-15+ ounces – keep in mind that the strain (genetics) and any plant training you do will make a huge difference in your final yields. This LED model has performed better than most others I’ve tried so far.

I grew these cannabis plants under an HLG 300 V2 R-Spec LED grow light (view the grow journal). The 300L is the same light but longer (where the “L” comes from) to improve light coverage.

Cannabis plants grown by depthchargeseeds under an HLG 300 Quantum Board LED grow light (check out their Instagram profile!)

Cannabis plants growing under a Quantum Board LED grow light (HLG300) by depthchargeseeds

HLG 600 Quantum Board (R-Spec version recommended)

  • Price: $700
  • Grow Space: Up to 6′ x 6′ in the vegetative stage. 5’x5′ in the flowering stage.
  • Actual Power Consumption: 600W at full power, and can be dimmed down to 60W
  • How Far to Keep from Plants: 30-36″ for the vegetative stage. 24″ away in the flowering stage (may need to more distance for light-sensitive plants, or in a hot grow space).
  • Average Yields: 15 oz – 2 pounds – keep in mind that the strain (genetics) and any plant training you do makes a huge difference in your final yields. This light gets hot compared to a lot of other LEDs so you’ll need to use an exhaust fan and/or an AC to keep the grow space cool unless it’s naturally cold. Keep the temperature between 75-85°F (24-30°C) during the flowering stage to get the best yields.

Electric Sky 300 LED grow light (ES300)

Cannabis plants grown by cannabichiro (check out their Instagram profile for more!)

Quantum Board LED grow light (HLG550) by cannabichiro

Cannabis plant in DWC grown by rumplenuggrower (check out their Instagram profile for more!)

DWC-grown cannabis under an HLG500, grown by rumplenuggrower

 


 

4.) Mars Hydro (Best Coverage)

The Mars Hydro grow lights produce excellent PAR levels that are spread out evenly through the grow space. Although my plants grew slightly slower during the vegetative stage than some other LEDs, this light makes up for it in the flowering stage with massive buds. It seems engineered to excel in flowering.

Mars Hydro TSL 2000W

  • Price: $270
  • Grow Space: Designed for a 2’x4′ grow tent or space
  • Actual Power Consumption: 300W at full power, and can be dimmed
  • How Far to Keep from Plants: 24″ for the vegetative stage. 18-24″ away in the flowering stage
  • Average Yields: 7-14+ oz – keep in mind that the strain (genetics) and any plant training you do make a huge difference in your final yields.

The Mars Hydro TSL 2000W produces excellent PAR levels that are spread out evenly through the grow space.

My current Mars Hydro TSL 2000 tent at 24″ away. The buds are already beefy for just day 29 of flowering!

Now about those PAR levels. Let me show you how well this light covers a 2’x4′ grow tent by measuring the light levels 24″ away at 100% power

Here are the results with an Apogee MQ 500 PAR meter (measured in µmol m-2 s) when measuring light levels 24″ away at each plant. The light levels stay between 564-594 µmol m-2 s at the top of every plant. That means there is barely any variation of light levels throughout the tent. This is a huge advantage over other LED models where the plants on the sides are often underdeveloped.

Here’s what grower Andres had to say about the Mars TSL 2000, “my plants came out absolutely beautiful at harvest time and I could not have been happier”

Amanda used her Mars Hydro TSL 2000 in a 2’x4′ grow tent: “The plants absolutely love it & so do I. Very bright. I like having the dimmer on it as well. Well worth the money.”

 

 


 

5.) Custom LED Mix (Most Modular)

If you’ve got an unusually shaped grow space, or just want a lot of flexibility with your LED placement, sometimes the best option is to choose multiple LEDs. This is also a good way to start really small and scale up as needed.

It’s common for beginner growers to start with one small LED for their young plants, then add more lights as plants grow. For example, the grower below needed to increase his wattage overall so he added additional LEDs of a different size so he could focus a lot of light directly onto his plants.

Many growers mix and match LEDs, like Mental24 who used two Mars Hydro 1000s and one Spider Farmer SF-2000 to grow this beautiful harvest for less power and heat than a 600W HPS

Another popular option is to mix LEDs with other types of grow lights like HPS or LEC.

When you're using high-powered grow lights like HPS and LED, it's important to protect your eyes if you're spending a lot of time in the grow room!

But if you’re a beginner and afraid to completely take the plunge into growing, start small. Get a small cheap LED like the Spider Farmer SF1000D for $90 which only uses 87 watts. It is plenty for a small plant and you could even get a plant to grow buds and produce a few ounces. If you catch the growing bug then you could start adding more expensive lights to the mix. For example, Damian has been slowly adding more LEDs as his plants grow and he identifies dark spots.

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