Today you're getting a review of the best LED grow lights that you can currently buy.
You're also going to become an LED grow light expert in less than 5 minutes.
You're going to get a simplified buyer's guide that covers:
- 2 easy-to-use rules you can use to decide how strong of a grow light to get for your setup;
- A step-by-step process to rate any LED light, and;
- Tips to optimize the performance of your light and maximize your yield.
Let's get started with our most recommended LED grow light.
Quickly go to the…
1. Gavita Pro 1700E (Best Overall)
LED grow lights are evolving at a fast pace.
What was best 2 years ago, is now replaced with a new LED technology.
And when talking about new LED technology, the Gavita Pro 1700E grow lights are as new as it gets. New technology in LEDs usually means stronger light for less electricity.
Although the Gavita Pro 1700E is one of the more expensive LED grow lights …
When you look at the power of this light, you'll quickly understand why it has such a high price tag.
The Gavita Pro 1700E's output is rated at 1700 μmol/s. This is extremely high for an LED grow light. It's the strongest grow light on our list.
Not only is the strongest light on the list, when you look at its umol/j we can clearly it's also one of the most watt-efficient lights that you can get. It has an efficiency of 2.6 umol/j.
Pound for pound, it puts out the strongest light for an average surface area (4'x4′ to 5'x5′) of all the grow lights on our list.
But strong and efficient light isn't the only thing the Gavita Pro 1700E has going for it …
Although white light was the preferred type of light 1-2 years ago (and it kind of still is), recent insights show that white light could benefit from supplemental light that falls within the deep- and far-red spectrum.
The deep- and far-red spectra of light are thought to be needed for the ‘Emerson effect'. The Emerson effect refers to the notion that two photosystems, one that is sensitive to the deep-red spectrum (680 nm) and one that is sensitive to the far-red spectrum (680+ nm), work together to optimize electron transport and photosynthetic rates.
Although much better than with ‘blurple' lights, the coverage of the deep-red and far-red spectrum with white light isn't truly optimal.
The Gavita Pro 1700E solves this issue by supplementing the powerful Samsung LM301B diodes with Osram deep-red LED diodes.
This means that this light even resembles the sun more closely than LED lights operating with only ‘white light' LED diodes.
Of course, as you would expect from a premium LED grow light, you also get great build-quality with the Gavita Pro 1700E:
It comes with eight passively cooled LED bars that provide a very even light intensity across the whole canopy and keep the noise down.
You probably won't need any additional cooling with the Gavita Pro 1700E, it's cooling mechanism is extremely effective.
The Gavita Pro 1700E is currently the best LED grow light that you can get. But you have to be prepared to pay its premium price tag.
Next up …
2. Horticulture Lighting Group HLG 550 V2 R Spec (Best Value for Money)
These HLG lights are an upgrade from the original HLG 550 V2 model.
The major upgrades of the HLG 550 V2 R Spec compared to the original model are:
- Supplemental light that covers the deep-red and far-red wavelengths, and;
- Slightly stronger light intensity, and;
- Slightly more efficient when we look at the umol/j (2.49 vs 2.6).
The R Spec version only made the original better and the original HLG 550 V2 was already rated as our best-rated LED grow light for 2019.
They were one of the first and few affordable LED grow lights that made use of ‘white light' quantum boards.
When growing plants, white light is preferred to your regular ‘blurple' LED grow light (blurple lights are predominantly blue and red spectrum lights, 90% of budget LED grow lights are blurple lights).
White light has a higher light-intensity in the full spectrum of ‘photosynthetically active radiation‘ (PAR). White light covers the full spectrum of wavelengths that are used by plants to grow and bloom MUCH better than blue or red lights.
White light more closely resembles the sun than blurple light and results in higher quality yield compared to blurple lights. Blurple lights have mostly high light output in the blue and red wavelengths of PAR.
And while blurple lights get the job done, time and time again we have seen proof of the fact that white light results in more and better quality yield.
Now you understand why white light is always preferred over blurple lights, let's take a look at the best white-light LED diodes that are currently available for non-commercial growers.
Currently, the Samsung LM301B diodes are one of the most power-efficient LED diodes you can use to grow your plants, and these are exactly the diodes that you'll find in HLG grow lights.
Any LED grow light that makes use of Samsung LM301B diodes is going to be great for your yield and your electricity bill.
Samsung LM301B diodes:
- Cover a wide spectrum of PAR, and;
- Produce more intense light with fewer watts than other types of LED diodes like Epistar and even Cree.
With Samsung LM301B diodes, you won't only be able to easily create a grow setup with a maximized light intensity and therefore yield, but you'll also do it with the least amount of electricity used.
Not only are Samsung LM301B diodes LED diodes currently one of the best LED chips in terms of PAR-coverage and light-intensity, but they're also the best-value-for-money LED diodes that you can get (will keep the cost of electricity down).
The only technology that comes somewhat close in terms of PAR spectrum coverage, light intensity, and PAR/PPFD efficiency, is COB LED (chip-on-board LED).
And although COB technology will result in amazing quality yield as well, you can get the same result with fewer watts (and a lower electricity bill) when using Samsung LM301B diodes.
When it comes to LED grow lights with Samsung LM301B diodes you have a few options. But if want your LED grow light to make use of Samsung LM301B diodes AND want:
- Great build quality;
- Supplemental light that covers the deep-red and far-red wavelengths;
- Run cool, and;
- Last longer than 1 year,
the HLG 550 V2 R Spec, together with the Gavita Pro 1700E are on top of that list.
Especially the cooling mechanism and proper spread of diodes are two extremely important factors that can make or break an LED grow light.
The passive cooling mechanism of the Horticulture Lighting Group quantum boards is designed very effectively with heatsinks. With most of their models, you probably won't need any active cooling (although it always helps).
Combine this effective cooling with the most power-efficient white-light diodes and the right spread of diodes, and you have the perfect combination of grow light features to get an amazing yield while keeping the electricity bill down.
Next up …
3. Spider Farmer SF (Best Budget Light)
If you want to experience the power of Samsung LM301B diodes, but don't want to spend $800+ on a premium LED grow light from Gavita or HLG …
You'll be happy to know that there are cheaper alternatives.
Our most recommended cheaper alternative if you want the powerful and cost-efficient Samsung LM301B diodes is currently the Spider Farmer SF LED grow light.
While the build quality of the Spider Farmer SF might not be as good as the Gavita or HLG lights …
The light intensity is only slightly worse …
But MUCH better than other budget LED grow lights.
Of course, you can expect a similar efficiency with the Spider Farmer SF compared to the premium lights that come with Samsung LM301B LED diodes. When we look at the advertised umol/j, we can see that the Spider Farmer SF has an advertised efficiency of 2.7 umol/j.
This makes the Spider Farmer SF, theoretically, even more efficient than the Gavita Pro 1700E.
What's even better?
Although the ‘white light' emitted from the LM301B LED diodes covers a much wider spectrum of PAR than the average ‘blurple' light …
White light doesn't cover the deep- and far-red spectra of PAR as much as you would like.
Well, Spider Farmer lights are supplemented with deep red LED diodes and infra-red chips.
This makes the Spider Farmer SF lights cover an almost as wide spectrum of PAR as the Gavita Pro 1700E and the HLG 550 V2 R Spec.
Next up …
4. Amare SolarECLIPSE (Best Build Quality)
If you're looking to replicate the sun, the Amare SolarECLIPSE will get you very close.
This is a full-spectrum light in the most real sense of the word:
While 90% of LED grow lights are so-called ‘blurple' lights, mainly providing PAR-output in the blue and red spectra, the Amare SolarECLIPSE is providing a very high PAR-output in the FULL spectrum, including the green spectrum!
It has a very balanced ratio of wavelengths, including the far-red spectrum which is needed for the Emerson effect.
It gets even better:
UV-light has been proven to increase THC-percentages in cannabis, and this is one of the few lights that have an UVB-bulb.
This light is a real powerhouse and literally replicates the sun. Don't take my word for it. If you check the PPFD readings, you'll see this light's PPFD values are off the charts. Not only regarding pure output, but also the coverage area. The coverage area of this light is bigger than other same-watt budget lights on the list when using the ‘minimum of PPFD of 510 μmol m(-2)s(-1) for the full coverage area' rule.
When looking at the actual power draw of this light, you'll see this light has a very high PPFD output per watt (PPFD/WATTS).
Here's how they achieved this:
The LED chips used in this light are based on COB technology (chip on board). COB LEDs are more powerful and efficient, last longer than regular LED diodes, have a more balanced spectrum of wavelengths, and are much easier on the eyes than specific color LED chips.
The main downside of COB is that they're a single-point light source and the spread isn't the best, but Amare counteracted this by providing supplemental CREE chips.
Here's the exact composition of this light:
- 6x CXB-3070's, and;
- 60x CREE XP-G3 & XP-E2 Monos.
The Amare SolarECLIPSE has the best build quality on the list. The cooling is really on point, you won't need any additional cooling with this light. plus you get a 5-year warranty in case anything goes wrong. 5-years of warranty is above-average in the LED industry (the average is 2-3 years), shows you how much they trust their lights.
What's the bottom line?
If you value build-quality over results a bit more …
The Amare SolarECLIPSE is the light you should get.
- Click to see the most recent price – (LEDGrowLightsDepot)
Last on our list is the…
Next up we have another budget-light, the:
5. VIPARSPECTRA Reflector Series (Cheapest)
The VIPARSPECTRA Reflector is similar to the MarsHydro Mars Pro II Epistar light. It’s a Chinese budget light which provides excellent value for its price.
The quantity and quality of your yield with these lights will be slightly worse than with the MarsHydro Mars Pro II Epistar (when comparing the same watts per square foot).
This comes as no surprise as the light intensity (PPFD) of this light is the lowest on the list (still decent though).
The build quality of this light is also slightly worse. But it's also quite a bit of a cheaper light than the other lights in the list!
This is the cheapest light on the list.
Go cheaper than this, and you'll probably waste money on a subpar light. The VIPARSPECTRA Reflector is the cheapest you should go with a LED grow light.
Even though the VIPARSPECTRA covers the full PAR spectrum, including the green spectrum, plus the far-red spectrum (for the Emerson effect), when you look at the ratios, you'll see the blue spectrum has the highest proportion of the light's output.
What this means is that especially in the flowering stage (in which the green to red spectrum is most important), you'll find this light can disappoint compared to the other lights on the list. So don't be expecting miracles from this light in the flowering stage.
But because its price is so low, you can easily get a few VIPARSPECTRA lights, for the same cost as a high-end light like the Gavita Pro 1700E (keep in mind that 2 Viparspectra lights still won't give an as good of a result as one high-end light like those from Gavita or Horticulture Lighting Group).
If you're looking for a budget-light, I still recommend the MarsHydro Mars Pro II Epistar as the number 1 budget-light.
It's higher quality in all aspects, and MarsHydro has been around longer and built a more solid reputation as a manufacturer of budget LED lights.
But if you're looking for the cheapest of the cheapest, which will still get you good results…
This is the light you should go for.
For those who are ready to take it a step up and don't want to settle for a ‘decent' light, let’s continue.
Next up is the former KING of LED lights, the…
LED Light Accessories
Most lights come with a hanging kit.
But if not, you will need a way to hang your lights.
And the best way to do that is with some quality:
- Rope Ratchets – (Amazon)
These rope ratchets are sturdy as hell.
But again, most lights come with a hanging kit!
If you want to make things easy on yourself, you should also get a timer to control your light cycles:
- Honeywell Timer – (Amazon)
Otherwise, you'll have to manually turn on/off your lights, which is a hassle, trust me.
How to Rate LED Grow Lights
Light is the main ingredient for growing high yield plants.
But how can you rate the quality of light?
Well, it’s precisely the:
- Range and ratio of different wavelengths/colors of light,
- Your light’s intensity, and
- Your light's efficiency,
which are the most important when rating a LED light.
And the only true way to measure the range of wavelengths and your light’s true intensity is not by watts per square foot or lumens as most people think, but by:
- PPFD, and to a lesser extent,
- PPFD/Watt ratio.
Let me explain what these abbreviations mean.
What’s PAR and Why It’s Important
PAR stands for ‘Photosynthetically Active Radiation.’
And although some LED light manufacturers (wrongly) use the term PAR when talking about a light's intensity, PAR is not a way to measure the intensity of your light.
PAR is the range for all the different wavelengths/colors of light that plants use for photosynthesis.
For your plants to grow optimally, your LED light should have all the different wavelengths/colors of light that makeup PAR. But especially important are:
- The blue wavelengths (for vegetative growth), and;
- The orange/red wavelengths (for the flowering process).
Luckily, most LED manufacturers are aware of PAR and design their lights in such a way that most of the wavelengths/colors of light that fall within the PAR-range are present.
And the lights in this list have specific vegetation/flowering settings with optimized spectra for that particular stage in the growth cycle. and, you can quickly activate these specific settings with a simple switch.
This is also the main reason why LED lights are more efficient than HID lights (HPS and MH).
HID lights emit ALL the different wavelengths/colors all the time. This even includes wavelength/colors that fall outside of the PAR range!
What this means is that HID lights waste quite a lot of electricity, because they're using power for colors/wavelengths that fall outside of the PAR range and thus are useless for your plants!
If you get the right LED light, your light will mostly have the wavelengths/colors of light that fall into the range of PAR and wavelengths that fall into the deep and far-red spectrum (which are essential for the Emerson effect). Your light will largely emit light that's actually being used by your plants for photosynthesis. This way, little to no electricity goes to waste.
But as you now understand:
PAR doesn’t say anything about the light’s intensity (in all these different wavelengths). Your light's intensity is key to rating a grow-light and getting strong plants with monster yields as well.
What’s PPFD and Why It’s Important
PPFD stands for ‘Photosynthetic Photon Flux Density.’
PPFD is a measurement of light intensity, and it says how many light photons that fall within the PAR-range (expressed in micromoles) hit a given square meter per second: μmol m(-2)s(-1).
A photon is the most basic and smallest unit of light.
Essentially, what PPFD does, is measure the intensity of your light.
This means to rate the quality of a LED light, PPFD is one of the most critical metrics.
Of course, there are also metrics like:
- Build quality;
- How much heat the light generates;
- Reputation and reliability, and;
- Customer service;
That you should consider when choosing a LED grow light.
But PPFD is what mostly matters to your plants. And what matters most are the PPFD values in the orange/red wavelengths, because these are the wavelengths that have the most impact on your yield in the flowering stage of your plants.
Below is shown how much PPFD is needed as a minimum for your Cannabis plants to grow and give you at least some yield:
- 255 μmol m(-2)s(-1) – 347 μmol m(-2)s(-1) PPFD on a 24 hours light schedule.
- 383 μmol m(-2)s(-1) – 520 μmol m(-2)s(-1) PPFD on a 18 hours light schedule.
- 510 μmol m(-2)s(-1) – 694 μmol m(-2)s(-1) PPFD on a 12 hours light schedule.
I can't emphasize this enough:
The guideline above is the minimum PPFD you'll need to produce a decent yield.
Your plants will grow and yield at a much better rate in the flowering stage if you get close to the optimum PPFD value between:
- 700 – 1500 μmol m(-2)s(-1)
The range above is the range where your plants will thrive in the flowering-stage on anything except a 24-hour light schedule, but a 24-hour light schedule isn't the best practice anyway.
But keep in mind this is the average PPFD value.
For optimal results, you never want your PPFD to drop below 510 μmol m(-2)s(-1) and never to go above 1500 μmol m(-2)s(-1) at any given point of the coverage area.
The exact optimum PPFD value is a controversial subject, and is among other things, highly dependent on:
- Whether you're supplementing with CO2;
- The growth stage in which your plants are: in the flowering stage your plants will need more intense light;
- Your specific strain: Sativa-dominant strains thrive under more intense light than Indica-dominant strains, and;
- Your light cycle: the longer your period of light, the lower the optimal PPFD value is and vice versa.
Can a light be too intense?
The threshold of ‘too intense' light is above 1500 μmol m(-2)s(-1). The exact value is also dependent on several factors like CO2-levels, your strain, and temperature. But you won’t get very quickly close to threshold with the lights on this list (as long as you respect the minimum height distance as advertised by the manufacturer, more about that later).
There’s a HUGE ‘but’ with PPFD though…
Even if we know the PPFD of a particular LED light, we usually don’t see how it was measured.
If you measure the PPFD in the area RIGHT below the light (in the center), you will get different values than further to the sides and corners. The further you get from the center of your LED light, the quicker the PPFD values drop.
You will also get different PPFD values if you measure from different heights. The closer you measure to the light, the higher your PPFD will be.
So when reading PPFD values, it needs to be 100% clear what:
- The distance was between the LED light and the canopy (or simply the floor);
- What the PPFD values were in the different parts of the coverage area, not only the center, and from different heights, and;
- The PPFD values are for the different wavelengths within the PAR-range (this one is tricky and is almost never provided, but in an ideal world we would have this info as well).
If you have the PPFD values, including all this information, you have a reliable PPFD measurement, and you'll know for sure how one light compares to another regarding light intensity.
But the sad truth is:
Most LED light manufacturers don't provide all these PPFD-reading-related background information.
Either they provide no PPFD values at all or a general PPFD value, with no background information.
A single PPFD value without any background information is useless information, as it doesn’t tell us exactly about the light’s spread, its penetration or even its intensity.
Note: Some LED manufacturers do provide PAR value charts (PPFD charts) of the light's coverage area. It's always worth it to ask for such a chart. Here's how such a chart looks like:
If you want an amazing yield, the PPFD should never drop below 510 μmol m(-2)s(-1) in the flowering stage. And as you can see, although the light gets advertised with a 4×4 ft. coverage area, should you grow according to the 510 μmol m(-2)s(-1) rule, it would only cover between 2×2 ft. and 3×3 ft. So always take the coverage area of the manufacturer with a grain of salt.
If PPFD isn’t 100% reliable either…what’s left?
We don’t wholly toss away PPFD in the garbage can.
Although it’s not the most reliable metric because of the often-lacking background information, it does say something (depending on the degree of transparency of the LED light manufacturer).
But if we want to get a complete picture in a world where LED manufacturers don't provide reliable PPFD measurements…
We’re also simply going to have to look at the results of different lights in different growing setups, which means reading and comparing lots of grow journals.
And EVEN this rating process has many caveats.
You can’t just compare one setup to another, there are countless variables that impact the yield of a grow beside lighting.
Nonetheless, when we compare similar grow setups, where only the LED light used, is different, we can very cautiously conclude which LED lights provide a higher yield than others.
So when rating the quality of the light that comes out of a LED grow light, these are the things we look at:
- PAR: which wavelengths have the highest output by the light. You want blue and red wavelengths mostly, but not only! You want the full PAR spectrum, including the greens. Plus the far-red spectrum (which falls outside of PAR).
- PPFD: are there any values provided for different wavelengths in the PAR-range and do we know how it's measured and calculated.
- Grow journals: compare the yield of in the same setups, where only the light differs (has many caveats as well!).
The bottom line when rating LED lights is:
Scientifically and 100% objectively rating LED lights is quite tricky at this time.
If manufacturers brought out independently tested PPFD measurements with all the before mentioned background information, it would be easy.
Nonetheless, using PAR, PPFD and grow journals, we can get an excellent idea of the quality of light coming out of a particular LED light.
Now you know how at least the quality of light coming out of a LED light should be rated, it’s time you understand how many watts to get for your specific space/setup.
Although watts per square foot doesn't say much about the light's intensity, it currently is a decent way to decide how big and powerful of a light you need to get for the size of your specific grow setup.
Unless of course, you've got reliable PPFD / PAR value charts, but you probably won't!
How to Choose a LED Light for Your Specific Setup Using Watts
As a general guideline, you should try to get a minimum of 50 watts per square foot with a LED grow light. This guideline is by no means perfect but will help to get you started.
50 watts per square foot means that:
- A 400W LED grow light will cover a 2.5 X 2.5 ft space.
- A 900W LED grow light will cover a 4 X 4ft space.
- A 1600W LED grow light will cover a 5 X 5ft space.
But here's the kicker:
I'm talking about the real wattage value! Im talking about the actual power draw, the actual watts that your light pulls out of the wall.
Let me explain.
Many LED light manufacturers give their specific model a name like ‘MARS II 400W'. The confusing part here is the ‘400W'. A MARS II 400W does not have a real wattage value of 400. Its actual power draw is 162 watts.
So ALWAYS look for the true wattage value/actual power draw of a light.
Don't get confused by the name of the light.
Below you can see an example of what I mean:
Example: This means that with a 3×3 ft. space (9 sq. ft.), you will need at least 9×50 = 450 watts of actual power draw.
Why does all of this matter?
Most lights get advertised with a coverage area that's grossly overstated not only when keeping the minimum of PPFD of 510 μmol m(-2)s(-1) rule in mind, but also when keeping the minimum of 50 watts per square foot in mind.
What's the bottom line when choosing a specific LED model?
There are 2 ways you can choose a specific model:
- Best method: You have PPFD / PAR-value charts, and you make sure that no part of your growing area goes below a PPFD of 510 μmol m(-2)s(-1);
- Realistic method: You don't have PPFD / PAR-value charts, and you go for a minimum of 50 watts per square foot.
The first method will result in a better quality yield but will be more expensive (you'll need more ‘light' to achieve this), and you'll need reliable PAR-value charts which are often not provided.
The second method will result in a decent yield and will be cheaper and easier most of the time (most LED manufacturers don't provide PPFD / PAR-value charts…yet).
Also, do realize the following when choosing a specific model:
In many cases, it’s better to get multiple lower wattage LED lights instead of getting a single high wattage LED light, and position them in such a way that light from different angles covers your plants.
This is because LED doesn’t have the best spread compared to other types of lights, and the more lights you have, the better you can position them and the better the spread of your light will be.
One last topic before we get to the 5 best led grow lights:
What's the right distance to keep your LED lights from your plants
It’s crucial that you put your lights as close as possible to your plants, without causing light burn, because this will directly affect the potency of your buds.
But it's just as important not to put your lights too close to your plants.
But what’s ‘too close’?
This is highly dependent on the light's brand and model.
The more powerful the light, the higher the minimum distance between your light and your canopy is.
LED manufacturers always provide minimum distances with their products, and you should use these.
Ultimately, you're going to keep a close eye on your plants and act accordingly:
- Raise them in a few inch increments when they show signs of stress/light burn, and;
- Lower them when you feel your plants need more intensity.
One Last Word
You don’t have to go for a premade LED light.
If you’re tech-savvy, you could build your own LED kit.
There are many guides and tutorials on the web, which will show you how to build a potent LED light that will be quite a bit cheaper than the premium premade LED lights, but will provide close to the same quality of light.
Just prepare and take your time to do all of your homework in case you go this route.
If you want to make sure you have all the supplies to grow your marijuana, check the following guide:
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