Best LED Grow Lights in 2021: Most Powerful Indoor Grow Lights

By  //  July 30, 2021

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Whether you are a farmer or someone who is into horticulture as a hobby, knowing about artificial lighting and the options available in the market is essential.

Hemp growers or cannabis cultivators are likely to be familiar with LED grow lights. They are alternatives to sunlight and are used to provide light to the plants just as well, if not better.

The market hosts options such as the conventional HPS lights (high-pressure sodium lights) and CFLs (compact fluorescent lamps). In addition to the aforementioned traditional choices, there is the LED grow light. LED is believed to be a better option than the other two, and for good reasons.

For about a decade, NASA experimented with LED technology in stimulating plant growth. Photosynthesis utilizes light of wavelength 400-700 nanometers, similar to the visible light spectrum.

The lamps that are traditionally used for indoor agriculture emit radiation in the form of heat and do not fall in this spectrum. LEDs can produce light within the required spectrum by simply choosing the appropriate material for manufacturing the LED. 

Best LED Grow Lights

  1. Spider Farmer SF Series: Overall Best LED Grow Light
  2. Horticulture Lighting Group HLG 650r: Best Affordable Light
  3. Gavita Pro 1700e LED: Durable and Efficient Indoor Grow Light

Why LED Grow Lights Are Garnering Attention

  • Like sunlight, LED grow lights can offer a wide range of wavelengths that facilitate growing healthy crops. Additionally, yield can be improved with the use of LED lights.
  • When compared to the numerous other choices of lighting, LED is worth the money for farmers. The lighting is efficient and the intensity is ideal for growing plants.
  • Even though the initial investment in LED grow lights is steep, the savings along the way justify the cost. In addition, LED grow lights are long-lasting and durable. 
  • In regard to efficiency, power consumption it is relatively low when compared to other lamps. Also, conservation of energy criteria is met in the process. 
  • The heat emitted by LEDs is less. This feature enables you to install the LEDs near the plants without the concern of harming them.
  • LEDs do not contribute to chemical contamination of the air or soil.
  • Durability and extended shelf-life stand out when compared to other types of lighting.

Moreover, LED grow lights can be developed in such a way to provide the ideal wavelength of light for growing plants. By doing this, the plants can grow in the most optimal lighting condition that is even better than sunlight since there are no unwanted wavelengths.

To summarize, LED grow lights offer a wide spectrum of light, encompassing wavelengths of the visible spectrum and the invisible spectrum. This provides the added advantages of high yield in plant growth minus the concerns of negatively impacting crops or your eyes.

Best LED Grow Lights

#1. Spider Farmer SF Series: Overall Best LED Grow Light

The Spider Farmer products are cost-effective. Like most big brands, the Spider Farmer Company uses quality materials and components, such as the LM301B diodes from Samsung and the Meanwell drivers. 

The efficiency and light intensity of the series match closely with that of bigger brands. 

The popular series from Spider Farmer that is also suitable for growing cannabis indoors include

Light penetration is on par or even better than bigger companies. Power consumption for SF1000, SF2000 and SF4000 is 100W, 200W and 450W respectively while the flowering footprint is 2x2ft, 2x4ft and 4x4ft for SF1000, SF2000 and SF4000 respectively. Moving on to the Vegetative footprint, the values for SF1000, SF2000, and SF4000 are 2.5×2.5ft, 3x4ft, and 5x5ft, respectively. 

Lighting Efficiency and Spectrum

This product looks like it can give tough competition to big brands such as the Horticulture lighting group and Gavita Pro. Since the diodes used are LM310B that offer a wide spectrum including deep-red and infra-red compared to the conventional lighting and also that it is available at an affordable price, the SpiderFarmer series is a popular product in the market. 

Lighting efficiency is 2.7umol/j. Furthermore, the SF series is also equipped with a knob for dimming. The newest model, SF-7000, has an efficiency of 2.9umol/j, the highest in the market.

The SF series is ideal for all growth stages. The full spectrum includes white, red, blue, and IR (IR760nm, 660nm, 5000K, and 3000K). The 3000K diodes provide reddish light while the 5000k provide more blueish. The IR 760nm and 660nm red are particularly beneficial during bloom. Yield is enhanced, and the flowering stage is accelerated. 


SF series LED lighting systems usually do not need any cooling. However, during summers or when it is very hot, the company recommends using cooling fans.


  • Input Voltage AC 100 to 277V
  • Frequency 50 to 60 Hz
  • Power Input values are 100W for SF-1000, 200W for SF-2000 and 450W for SF-4000
  • The number of LEDs is 218 pieces for SF-1000, 606 pieces for SF-2000, and 1212 pieces for SF-4000
  • Full spectrum: white, red, blue, and IR of 3000K, 5000K, 66nm, and IR 760nm
  • High Energy Efficiency: 2.7 umol/J with the latest SF7000 at 2.9 umol/J


The Spider-Farmer website is user-friendly. The shopping process is easy and straightforward.

Certifications and Laboratory Testing

The product is certified by Intertek and is also CE, and UL certified.

The product goes through durability tests and QC tests before shipment.

Top Features

  • Sturdy board frame with LEDs
  • Free of noise 
  • Superior quality at a relatively lower cost in comparison with other products in the market
  • Main light switch control
  • Daisy Chain Dimming
  • Uniform PPFD
  • 3-year warranty
  • The return policy states that it can be returned or replaced within 30 days of delivery

⇒ Click Here to Visit the Official Website of Spider Farmer SF Series

#2. Horticulture Lighting Group HLG 650r – Best Affordable Lights

Indoor horticulture, specifically for commercial purposes, is bound to benefit from HLG 650R. Deemed one of the best lighting systems, this lighting from Horticulture Lighting Group has a proven record of satisfied customers. 

HLG 650R’s increased PPF or photosynthetic photon flux equivalent to 1770 µmol/s (quantity of light particles emitted per second), implies better light intensity, and the lighting system has improved system efficacy of 2.81 μmol/joule

Let’s move on to the details of the lighting system:

Lighting Efficacy and Spectrum

HLG 650R has four quantum boards that are of high efficiency. They are custom made and are full-spectrum white and 660nm red boards. The Quantum board, QB 648, is from Samsung, and so are the diodes, Samsung LM301H, and Deep Red diodes.

With regards to efficiency, intensity, and light output, the brand tops the market. 

Another impressive feature of the lighting system is the 60 to 630 watts dimmable design.

Most grow light systems emit light that is termed blurple, meaning encompassing red and blue spectrum lights. Nevertheless, HLG 650R is superior as it covers a complete full-spectrum white light. PAR stands for photosynthetically active radiation, which includes wavelengths of yellow and green. Thus, the red and blue wavelengths with the yellow and green, in addition to far-red, are all covered in HLG 650R. 

Benefits of Added Wavelengths 

The Emerson Effect is the increase in photosynthesis rate when plants are exposed to the light of 670nm wavelength, which corresponds to red light, and wavelength of 700nm, which corresponds to far-red light. Far-red light increases the plant’s ability to capture light. Additionally, far-red light plays a vital role in the regulation of flowering. 

The full-spectrum light enables shortening the flowering cycle of the cannabis by up to 4 days in comparison to standard spectrum lamps.

Additionally, a comparison of HPS lighting and LED indicated that flowering time can be reduced by nearly 12 days when LED is employed. 

Studies indicate that HPS light fuels plants to grow tall and produce flowers of more dry weight, while LED enables plants to yield an enhanced concentration of THC and CBD. The bottom line is that the quality of cannabis is dependent on an optimized spectrum of light. 

The diodes used by HLG 650R and LM301H are considered ideal diodes due to better light intensity and coverage regarding PAR (photosynthetically active radiation). 

COB (chip on board) LED technology is efficient and offers spectrum coverage suitable from a PAR point of view. Additionally, light intensity, yield, quality, and efficiency are also superior with COB LEDs. However, the COB LED cost is higher than the LM301H diodes from Samsung that HLG employs. 

The expense involved in LM301H diodes is also on the higher side, but the cost seems to be reasonable considering the long-term output. 


The HLG 650R boards are designed in such a manner that the crops are exposed to light that serves as a perfect canopy facilitating light penetration with diodes placed appropriately on the board, which in turn leads to higher yield while ensuring the system is energy efficient with low electricity bills.

Cooling Mechanism 

There are heat sinks integrated into the quantum boards that ensure passive cooling. Horticulture Lighting Group employs a similar approach on all of its quantum boards. The need may not arise, but the company provides tips on the website for incorporating active cooling. 


  • Power rating: 60 to 630 watts
  • Voltage: 100-277 VAC 50-60Hz
  • Flowering Footprint: 5’x5’ at 30”
  • Total Output: 1770PPF
  • Veg Footprint: 7’x7’ at 48”
  • System PPF Efficacy: 2.81 μmol/joule


The horticulture lighting group website is easy to navigate and contains information about product specifications, such as efficacy and output. There are also useful calculators for converting LUX to PPFD, PPF to PPFD, and watts to BTU, and also the calculator to assess needed cooling. Additionally, there are elaborate videos on the website guiding through the installation process and other relevant videos. 

Certifications and Laboratory Testing

Intertek, a leading Total Quality Assurance provider based out of London, certified the HLG product. CSA certification and UL standards have verified the product. Horticulture Lighting Group has partnered with Light Laboratory to test each batch of the product.   

Top Features

  • 2.81 PPF/W Efficiency 
  • 1770 PPF Output 
  • Quantum Board® created by Samsung (called QB 648)
  • Passive-cooled design
  • Better canopy light penetration due to diffused light
  • Dimmable design covering 60 to 630 Watts 
  • Power supply, which is based on advanced Auto-sensing suitable for 277VAC, 240VAC, and 120VAC
  • It comes with a warranty of 3 Years 

⇒ Click Here to Visit the Official Website of Horticulture Lighting Group HLG 650r

#3. Gavita Pro 1700e LED – Durable and Efficient Indoor Grow Light

Gavita is a well-known brand in the horticultural lighting arena. The Gavita Pro 1700e LED is designed to provide more usable energy to the plants at less energy consumption. The product is a reliable full-term lighting system that ensures consistent results in addition to ensuring energy efficiency. 

Gavita LED is a good option for experienced growers or gardeners who intend to expand their gardens, mainly indoor gardens. The product is durable and efficient.

This Grow light is priced higher than most others. However, the high quality of the product makes it popular. It is backed by numerous positive reviews. 

The fixture has 8 LED bars. The design is unique. Since it is an open frame, it facilitates heat dissipation, and coverage of light is such that it is evenly distributed. 

The diodes are procured from Osram and Samsung, industry leaders in lighting. 

Efficacy is remarkable. It is equivalent to 2.6 μmol s-1 per watt. Additionally, the output is also impressive, pegged at 1700 μmol s-1 when operating at 645 watts.

The wet rating offered by the product ensures protection from water, dust, and oil, enabling you to mount or hang the light source anywhere. In other words, you have the flexibility of versatile placement within the growing space. 

Lighting Efficacy and Spectrum

The components used are from reliable sources. The system comes with Philips Advance drivers, Osram deep red LEDs, and Samsung white LEDs, a combination that assures enhanced performance and full-spectrum light. The Gavita 1700e functioning ensures the fixture life is optimized and spectral output is improved. 

The efficacy achieved by the system is 2.6 µmol s-1 per watt. The technology resembles natural sunlight to a significant extent. The fact that there are no fans due to LED bars that are passively cooled ensures that the probability of failure due to moving parts is less.

The system is ideal for indoor settings such as greenhouses, grow tents, and a grow room.


Gavita Pro 1700e provides even coverage of light. Everything under the grow light, at varied locations, gets uniform light and thus similar results. For maximum uniformity, the company recommends placing the fixture at the top at a distance of 24 to 36 inches from the plant.


The configuration or setup of the system includes 8 bars of LEDs that are passively cooled such that the distribution of light is even, and heat can be dissipated easily.


  • Efficacy is high: equivalent to 2.6 µmol s-1 per watt.
  • Input power at 100%: 645 watts
  • High-intensity output: 1700 µmol s-1
  • Input Voltage +/- 10%: 240 VAC
  • Operating temperature: 0-40° C
  • Input Current: 2.7A
  • Wieland RST 16i5 connector for Power Inlet
  • Product Weight: 12.9kg
  • Dimensions: 112 x 111 x 8.5 cm (LxWxH)
  • E-series adapter for External Dim


The website is straightforward, providing all the needed information without having to look around for it. There are options to find retailers and purchase the product or pre-order, depending on whether they are in stock. 

Certifications and Laboratory Testing

It is IP56 wet rated in Europe and IP66 wet rated. Additionally, it is FCC compliant and UL8800 compliant. Furthermore, it is DLC listed and CB and CE compliant. 

Top Features

  • The light spectrum is a balanced, broad, and full spectrum
  • HVAC requirement is reduced, up to 40% less
  • It is dimmable by up to 50% using the Gavita E-series LED adapter. 
  • High output, high efficiency
  • The 8-bar-set-up permits usage in tents, vertical racks, and low rooms.
  • The 8 LED bars that are passively cooled do not encompass any fans, thus devoid of moving parts.
  • Wet rating assures protection from oil, dust, and water, implying that it can be used in wet areas.
  • Daisy-chained splitters setup enables connecting 500 to 1000 LED fixtures.

⇒ Click Here to Visit the Official Website of Gavita Pro 1700e LED

Picking the Right Brand for Best LED Grow Lights

Quality LED grow lights generally last long. For up to ten years, the lights function with exceptional efficacy. Nevertheless, one has to choose LED lights carefully because the initial cost of the system is high. 

Furthermore, what you need to bear in mind is that there is a possibility that the system will be up and running for many hours in the day, particularly if it is intended for indoor growing, which in turn adds to the electricity bills.

Some important aspects that need to be looked into while procuring an LED system are listed below:

  • Factors Specific to the Product

These factors include spectrum, coverage, angle of the lens, wattage, heat output, laboratory tests, warranty, return policy, and product price.

  • Spectrum

Unlike the HPS lights, LED grow lights offer full-spectrum light. Reputed brands ensure the product is full-spectrum as better coverage is obtained in the process, similar to natural light. Big brands post details related to laboratory test reports with information related to PPFD and PAR on the website. Customers can access it easily.

  • Lens and Coverage 

A lighting system that covers every corner of the growing area or the farm is essential such that each plant receives light at the same efficiency. Heat, light spectrum, and intensity should all be the same for all plants. 

Additionally, the LED lens angle decides the intensity, how cool or hot, and the plants will be. The LED angle is also the determining factor for the light being diffused or direct. 

  • Wattage

It is a good idea to check the wattage and then purchase the lighting system considering that the farm may need less light and the wattage on the lighting system is in the 1000s, which may not be required. 

  • Heat Output

The lighting system’s heat output is an essential factor in choosing the grow light. While checking the heat output, the cooling method information needs to be looked into so that before installation, any extra fixtures can be incorporated. 

The proximity of the lighting system to plants also depends on the heat output. An effective and safe approach should be the focus so that plants benefit from the system but are not harmed by the heat.

  • Laboratory Tests

Availability of lab test results is good both for the company and for the customers. Businesses rely on trust. Providing customers all the information they need with regards to product safety and efficiency conveys to the customer the confidence the brand has in its product. Big brands make sure all the results are accessible on the website.

  • Return Policy and Warranty

Most reputed brands believe in the quality of the products they offer. Thus, there are return policies that these companies have in place if you are not satisfied with the product. 

Or if it does not yield results on the lines, you were expecting. The product can be returned to the company for a full refund in most cases, and partial refund in some situations, provided it is within the period stated in the return policy. 

  • Price

Choosing an expensive LED Grow light does not automatically serve the purpose of your horticulture farm. It is smarter to assess your requirements and pick an appropriate system. Bear in mind that there is a power bill attached to the system, implying costs involved include the initial cost and the on-going utility bills. 

Before you commit to purchasing a particular product, make sure you check the efficiency, light output, coverage, and all relevant aspects to ensure that you are spending for exactly what you need. 

Other Factors

  • Plant Type and The Phases of Growth

Not all plants are alike. Each requires a specific wavelength of light. Various growth phases require different wavelengths. To enable cannabis growth, both flower and stem, there is a need to include far red, that is, wavelengths in the range between 750nm and 780nm to the standard blue light. 

The purpose of blue light is to ensure the elongation of stems is uniform and shrinkage of the leaves is prevented. But only a small amount of light is required. Additionally, cannabinoid output or yield is enhanced with the red light. 

Studies indicate UV-B light elicits THC accumulation. UV-B corresponds to wavelengths in the range of 280nm to 315nm. THC concentrations have increased when cannabis was grown with supplemental UV-B radiation based on these studies. 

Experiments undertaken by growers of cannabis provide red light as these plants depend on an extended time of darkness and need the far-red wavelength towards the end of flowering. 

  • Requirements Based On Indoor And Outdoor Growing

Outdoor growers of cannabis enjoy natural sunlight’s benefits for a significant amount of time, while indoor growers need to ensure that adequate artificial lighting is provided. In either case, depending on the conditions, it is recommended that you gauge the lighting requirement and choose the appropriate LED Grow light system

  • Various Kinds Of LED Grow Lights

The various kinds of LED-based lighting for growing plants can be classified as Conventional panels, SpiderLED, Quantum Board LED, and COB Grow lights. There are positives and negatives attached to each of the lighting systems.

The conventional LED panels are boards that have compact lamps, including diodes with wattages in the low to the medium-range providing growers with advantages of the traditional grow lights. 

SpiderLED is similar to quantum boards. The extensions are like spider feet where the diodes are spaced out, rather than on a single board. Cost-wise, the SpiderLED sets are on the expensive side. However, growers have shown a preference for the product as they are effective. 

 When it comes to the quantum board, it was first utilized by the Horticulture lighting group that saw the potential in combining both styles (board style and spider style) for superior lighting. The quantum board style of lighting encompasses diodes of low wattage placed on the board-based design with an appropriate spread. 

The chip-on-board systems for lighting, also referred to as COB light systems, come with large LED bulbs. The numerous LED chips in individual LED bulbs are responsible for the intense rays, which are also bright. The arrangement is compact with a high concentration of chips. The lens that accompanies the bulb is powerful, ensuring the light is focused on the crops. 

Advantages of this system include higher penetration and increased volume in addition to the accelerated growth rate. Placement of the system needs to be done carefully, so you don’t place it too close to the plants. The downside is the electricity bill, which will be elevated with this system.  

Significance of Light Spectrum in Horticulture

We generally limit the assessment to the wattage and lumens, which is not a good practice when looking at LED grow lights. 

The efficiency and quality are gauged by analyzing the light intensity of the product, the efficiency of light, and the wavelength of light produced by the products. Key aspects are the wavelength of light, the color of the light, and light particle density. PAR, PPFD/watt, and PPFD are the metrics you need to look into. 

The outdoor growing of cannabis does not entail much thought with regards to lighting as the full spectrum is provided by the sun. Nevertheless, for indoor cultivation, the grower’s full spectrum needs to be created, or else photosynthesis will be affected. We can create the effect close to natural light by understanding PAR as well as PPFD. 

  • Significance of PAR

Near-ideal light wavelengths for growing plants are provided by LED grow lights, including the stages of flowering that are different from other growth stages. PAR stands for photosynthetically active radiation. 

The colors or wavelength that corresponds to is 400 nm-720nm. This is the wavelength needed for photosynthesis. In simple words, plants use this wavelength to produce food using other water, soil, and air elements. 

Farmers or, in general, plant growers want to ensure the plants are provided with all aspects for bearing healthy plants, whether it is cannabis or any other plant. So identifying the wavelength and light and their impact on growth is crucial. 

The flowering stage requires wavelengths between 620 nm and 70nm, corresponding to red and orange light, while the vegetative growth is positively influenced by the blue light of wavelengths 400-500nm. This aspect is controllable by using switches on the LED system to switch between the various light wavelengths. 

HID lights or high-intensity discharge lights, including MH and HPS lights, emit light of all wavelengths when in operation. That is when the system is up and running, without the flexibility to switch between wavelengths. Wavelengths outside of the PAR are also emitted. This entails a lot of power. In other words, the wastage of power in this arrangement is not a perfect set up. 

On the other hand, the LED system gives you the control. You can select the wavelengths based on need or stage of growth. The wavelengths to choose from include PAR and others beyond PAR, such as the far-red or deep red that facilitate high yields and grow healthy plants. 

PAR alone is not sufficient. The intensity of light is also critical for growing plants and obtaining high output, not to mention light penetration, which also plays an important role. That leads us to understand the relevance of PPFD. 

  • Significance of PPFD

PPFD stands for photosynthetic photon flux density. It measures how much PAR arrived at the plant. A more scientific explanation is the number of photosynthetically active photons that land on a certain surface per second. It is measured in micromoles per square meter per second (µmol/m²/s). 

The density of particles that reach the plant is an important criterion for plant growth as not all plants need the same amount of particle density. Some plants need to be in the shade, and numerous others require sunlight. 

The artificial light system’s placement needs careful consideration as the light proximity to plants could negatively impact plants when it is too close. 

The difference between PPF and PPFD is that PPF represents the number of photons that are emitted from a light source, while PPFD corresponds to the number of photons reaching a particular surface. PPF stands for photosynthetic photon flux. It is measured in μmol/s that is micromole per second. 

For grow lighting, the wavelengths are 400nm to 700nm. With regards to cannabis plants, the PPFD range is 510-694 µmol/m²/s for a 12-hour lighting system, 383 – 520 µmol/m²/s for an 18-hour lighting system, and 255 – 347 µmol/m²/s for a 24-hour lighting system.

For various stages of plant growth, the strength of light needed is differentiated as below.

For flowering, the light strength needed is high, in the range between 600 and 1000 µmol/m²/s, while early stages of vegetative growth require medium strength of light, equivalent to a range between 400 and 600 µmol/m²/s. Finally, the seedling development necessitates a light range of low strength between 200 and 400µmol/m²/s. 

Wavelengths of LED Grow Light

  • Blue light

The wavelength of blue light is 400nm to 500 nm. Blue light helps plants to grow. The absence of blue light leads to stunted growth. The leaves and branches turn out to be under-developed. 

The grow lights from major companies are developed to ensure that particular light is provided for a certain stage of plant growth, such as blue for a particular phase and red for another growth phase.

For the cannabis plant, blue needs to be reduced at the flowering stage so that the buds do not grow long and lean as lean and long buds mean lower cannabinoids. 

  • Red Light 

Red light corresponds to wavelengths between 620 nm and 720nm. This range of wavelengths is suitable for the flowering phase. Having said that, only red is not sufficient, and there should be a blue wavelength also for vegetative growth at early phases.  

  • UV Light

UV light or ultraviolet light corresponds to wavelengths below 400 nm. Wavelength in the range between 315 nm and 400 nm is UVA, while 280 nm to 315 nm is UVB and UVC corresponds to the range between 180 nm and 280 nm. 

The advanced LED grow lighting includes certain UV ranges to enable cannabinoid growth. CBD and THC are triggered by plants as protection from UV light. Trichomes are the cannabinoids that we need, and the plant produces as protection.

  • IR Light

IR or infrared light, as well as the near-infrared, correspond to wavelengths over 700 nm. This wavelength is responsible for the production of intense heat. 

Blooming in plants is regulated by some photo-sensitive reactions due to the far-red and infrared wavelengths, aided by the photoreceptor, phytochrome.  This process is different from photosynthesis, implying plants used different wavelengths for different purposes. 

Cannabis Growth Facilitated by LED Grow Lights

You can grow high potency cannabis plants and buds that are aromatic using LED grow lights. Various brands in the market are targeting the cannabis industry as it’s growing immensely. They have incorporated the lighting needs of cannabis growers when developing the LED grow lights. 

 The budding phase or the flowering stage of the cannabis plant requires infrared wavelengths and far-red light. The flowers, in particular, are benefited by this wavelength. 

 These days, the innovative LED lighting systems are designed so that light does not spread or diffuse too much, and light is focused on the plant. The advantages of doing this are lowering wastage, better yield, and required light penetration. 

 Also, make sure you check the other specifications and features such as cooling, heating, and other items from the list of specifications and features we have provided for each of the brands we have reviewed in this article.