November 5, 2020 10 min read
November 5, 2020
10 min read
ABOVE IMAGE: (4) of the Top LED Options Available at GrowersHouse for a (3′ x 3′) grow tent. Brands shown include – Horticulture Lighting Group (HLG) | Kind LED | California LightWorks | SpectrumKing

Over the last several years, LED (Light Emitting Diode) grow light technology has grown by leaps and bounds increasing both functional and cost-based efficiency. HID (High Intensity Discharge) Lamp setups were once the ‘norm’ for cultivating marijuana in an indoor grow room, but LEDs reduce energy consumption, save money, and can utilize a vast array of different spectrums ideal for crop cultivation.  

With legalization of cannabis cultivation becoming more commonplace nationwide small grow tents have become an exceedingly popular choice for individuals who wish to safely house and effectively produce high yields of cannabis using less effort. When combined with the right LED grow light(s) a Grow Tent is one of the best avenues for cultivating marijuana indoors.  

In this Article we will Discuss the Best (5) LED Lights for Use in a (3’ by 3’) Grow Tent! 

Advantages of LED Lights for a Grow Tent 

ABOVE IMAGE: (LEFT) (400-Watt)(HID)(High Intensity Discharge) Lamp Package including HPS+MH Compatible Ballast, Digilux (400W) HPS Bulb, Driver & (120-240VAC) Cord
(RIGHT) (320W) Prism Lighting Science Stealth LED Fixture

LEDs have many advantages over other types of light commonly used, but the most important is they provide growers with the most efficient source of PAR (Photosynthetically Active Radiation). In other words, LEDs produce wavelengths that fall within the ideal PAR range of (400-700nm), in a manner that’s uses the least amount of energy (Watts). 

For Example even the most energy efficient (double-ended) (HPS) (High Pressure Sodium) (HID) Lamp has a PAR energy efficiency  =  (<2.0 umols/Joule); where as a LED Lamp will generally have a PAR efficiency  =  (>2.0 umols/Joule) 

 Full List of Advantages of LEDs Include: 

  • Enormous Energy Savings (Compared to most HIDs about (40-50%) greater efficiency oper watt energy used)  
  • Long Life-Spans between (50,000 or More hours) for LED Diodes compared to only (2,000 – 3,000 hours) for (HID) bulbs. LED Diodes have No Filament to Burn.  
  • Ability to Customize Spectrum (Veg is promoted with cooler (Blue), while flowering is promoted with warmer (Red) tints of light)(More effective supplemental light source for greenhouse applications) 
  • LEDs are More Compact (Takes up less space than other lighting choices) 
  • Lower Heat Output (Keeps grow tent cooler | Lower risk of fire)  
  • Ability to Customize Light Angle (LEDs use lenses instead of reflectors) (Can penetrate canopy more effectively)
  • Ability to Customize Dimming Capabilities (efficient energy use growing from seed to harvest) 
  • Contains No Mercury (unlike compact fluorescent bulbs CFLs)  

Disadvantages of LEDs for a Grow Tent:

The most significant disadvantage to utilizing LEDs is the much higher upfront cost. In general, an LED will cost about (2x) as much as an (HID) lamp with the same wattage. However, if a grower has the capitol then the extra cost of the LED will be paid back over time thanks to the energy savings and much longer life span.  

However, LEDs can become a serious disadvantage is when cannabis is being cultivated in a colder environment. The heat created by (HID) lamps would be more beneficial to the crops making it the more appropriate option in this case. 

For those wishing to utilize a (3’ x 3’) grow tent in a cool environment a (400-Watt) MH/HPS (HID) Lamp would be a more appropriate option over an LED fixture.  

ABOVE IMAGE: (3′ x 3′) Grow Tent with a (400W) MH (HID) Lamp cultivating cannabis in a vegetative state.

Determining Specifications of Required LED  

Different (PAR) intensities and (DLI)(Daily Lighting Integrals) are required for different stages of cannabis-based growth. Specific growth states can also be promoted by utilizing specific PAR spectrums thereby increasing overall harvest yields. 

There are (2) Options for Consideration: 

Utilize (1) Powerful LED with Wide Spectrum  –>  Lower Capitol Cost + Easier to Maintain  -OR- Utilize (2) LEDs, One with Cool & One with Warm Spectrums  –>  Optimize Cannabis Yields

Important Lighting Terms:  

(PAR)(Photosynthetic Active Radiation)(400-700nm) – A specific range of light-based wavelengths that are absorbed and utilized by the many different types of chlorophyll in photosynthetically active crop species to create energy used for growing.  

The most significant PAR wavelengths absorbed by chlorophyll A & B are (430nm = Blue & 660nm = Red). Higher (430nm)(Blue) to (660nm)(Red) PAR ratios promote vegetative characteristics while the opposite promotes reproductive charateristics.  

(DLI)(Daily Light Integral) – The total amount of time crops must spend in (PAR) light over a 24-hr full day period. This value is critical for initiating changes in the growth state of cannabis; transitioning from vegetative state to a flowering (reproductive) state occurs when the DLI integral is brought down to (12-Hrs) per day.  

Important Lighting Requirements: 

Vegetative State | Requires Between (230 – 385 umols/m2/sec)(PAR) Using a (DLI) = (18-Hrs) Light : (6-Hrs) Dark

ABOVE IMAGE: Grow tent cultivating cannabis crops in the vegetative state using a LED fixture with full-spectrum capabilities creating the white colored light.

Reproductive State | Requires Between (475 – 800 umols/m2/sec)(PAR) Using a (DLI) = (12-Hrs) Light : (12-Hrs) Dark

ABOVE IMAGE: (3′ x 3′) Grow Tent cultivating cannabis in the reproductive (flowering) state using a LED fixture with full-spectrum capabilities and additional red (630nm) + far red (660nm) wavelengths to boost flower reproduction.

The (2) Primary Growth Stages of cannabis crops (Vegetative & Reproductive/Flowering) can be promoted by using spectrums ideally suited for each. Cooler spectrums carry higher ratios of blue to red PAR stimulating the production of leafy green growth whereas warmer spectrums carry higher ratios of red to blue PAR which stimulate flower production. 

If Savings and Ease of Use are Preferred Over Optimal Cannabis Yields then Utilize – (1) (3′ x 3′) Grow Tent + (1) LED with Wide (Full) Spectrum to cultivate cannabis through all growth stages.

ABOVE IMAGE: The HLG Elite 225 – (225W) LED Fixture is a low cost high efficiency lamp that incorporates full spectrum (white) as well as red (630nm) + far red (660nm) wavelengths enabling the cultivation of the cannabis through all it’s growth phases while still promoting flower production during the reproductive growth of cannabis. Also incorporates dimming which can be used to scale back the PAR intensity for vegetative growth.

This is by far the most common method of at home cannabis production since it offers the most cost effective solution. When only (1) LED is preferred the higher reproductive PAR range should be used to size the fixture. Since a (3′ x 3’) Grow Tent is (0.836x) the area of (1 m2) we will require an LED that has the ability to produce between:

(475 – 800)(umols/m2/sec) * (0.836)  =  (400 – 670)(umols/sec) @ (12-Hrs)(DLI)

It is Very Highly Recommended to Utilize an LED Model with Dimming Capabilities to lower the PAR an adequate range during vegetative growth. The ideal fixture PAR intensity range for vegetative growth in a (3′ x 3′) Grow Tent is calculated using the same formula as above but using the recommended PAR range for vegetative growth per unit area instead of reproductive:

(230 – 385)(umols/m2/sec) * (0.836x) = (200 – 320)(umols/sec) @ (18-Hrs)(DLI)

If Optimizing Cannabis Yields is Preferred Over Lower Capitol Cost and Ease of Use then Utilize(1) (3′ x 3′) Grow Tent + (1) Advanced LED with Customizable Spectrum

ABOVE IMAGE: The California LightWorks SolarSystem 275 LED Fixture is an advanced LED with a customizable PAR spectrum. This means the blue to red ratios, as well as other colors, can be adjusted to better suit the current growth phase of the cannabis crops involved.

– OR –

(2) (3′ x 3′) Grow Tents + (2) LEDs | (1) Cooler (Blue) to Promote Vegetative Growth + (1) Warmer (Red) to Promote Reproductive Growth

ABOVE IMAGE: The Spectrum King Mother’s Lil Helper (140-Watt) LED Grow Lamp is designed specifically for the cultivation of cannabis crops in the vegetative stage of growth providing a greater ratio of blue to red light.

These options are particularly useful for optimizing specific cannabis growth phases but requires a greater capitol cost and is more complex requiring the customization of spectrums -or- changing of fixtures to transition cannabis from vegetative to reproductive growth. Fixture sizing is determined in the same manner as calculated above and therefore retains the same values! 

Best LED Light Fixtures for a (3’ x 3’) Grow Tent  

Listed Below are the Best LED Models Selected from the Top LED Brands GrowersHouse Recommends for a (3’ x 3’) Grow Tent.

Top (5) LED Brands Include – HGL (Horticulture Group Lighting) | California LightWorks | Prism Lighting Science | KIND | Spectrum King

Wide (Full) Spectrum LED Lamps | Best Fixtures for Cultivating Cannabis though the Entire Growth Cycle 

Horticulture Lighting Group – HLG Elite 225 LED Grow Fixture | (225W) (120 – 277 VAC) 

ABOVE IMAGE: Image of the HLG Elite 225 LED Fixture from the side as well as from the bottom with the LED Diodes Illuminated.

The HLG Elite 225 – (225W) LED Fixture is a high efficiency model optimized for the cultivation of both vegetative and reproductive cannabis crops with the inclusion of white, red (630nm) and deep red (660nm) LED diodes to produce a unique design with very diverse spectrum. The addition of red and deep red wavelengths promotes more intensive reproductive growth leading to greater yields. The lamp also features a unique passive cooling design that saves energy, lowers noise and increases durability.

Overall, this LED fixture is ideally suited for growers who are looking for a balance between high PAR efficiency/effectiveness and lower cost. The fixture also has dimming capabilities between (90-225W) enabling PAR intensity adjustment, and associated energy savings, during vegetative growth. The lighting has an auto-sensing power supply that functions with capability to accept between 120VAC to 277VAC and comes with a (3-yr) warranty.  

PAR Output  =  (410 umols/sec)  | PAR Efficiency  =  (2.0 umols/Joule)  | Power  =  (225 Watts) 

California Light Works SolarXtreme 250 LED | (200-Watt) COB SX-250 (120VAC)

The SolarExtreme 250 LED (200W) Grow Fixture is simplified model with basic features (when compared to the Advanced SolarSystem Model) but incorporates high-quality LED diodes called (COBs)(Chip-On-Board). The (COB) LEDs incorporate direct AC driver technology making a separate driver unnecessary lowing overall cost while still retaining high PAR efficiency.

Overall, this LED fixture is ideally suited for growers who want the best PAR efficiencies at a reasonable cost. Has a lower PAR intensity making it more ideally suited for cultivation of smaller cannabis crops (Indica | Auto-Flowering); for larger cannabis crops (Sativa | Hybrid) utilize (2) SolarExtreme (250) LEDs.

Prism Lighting Science Stealth (320-Watt) LED Grow Fixture | (120-240VAC)

The Prism Lighting Science (320W) LED fixture is designed primarily for use with smaller-scale grow tents as well as to provide cannabis growers with a high quality, full-spectrum, PAR light source at the most affordable price possible.  

These fixtures utilize high-end technology including Epistar and Bridgelux LED diodes which are used to create a broad lighting spectrum that incorporates UV and IR wavelengths in addition to the standard PAR range. The addition of UV and IR spectrums helpsmodulate growth over time as well as produces buds with a higher resin content. Overall, this LED fixture is ideally suited for growers who want an LED that can still preform well and is avaliable for the lowest price of all LED fixture options. 

This fixture produces a higher PAR intensity equivalent to a (600-800W)(HID) which makes it an ideal option for the cultivation of larger cannabis strains (Sativa, Hybrid).  Doesn’t have dimming capabilities so highly recommend keeping fixture high above vegetative crops! Fixtures includes a power cord and hanging brackets in addition to a (2-yr) warranty.  

Grow Stage Specific + Advanced Spectrum LED Lamps | Best Fixtures for Optimizing Cannabis Cultivation During Specific Growth Stages

California Light Works SolarSystem 275 Advanced LED | (200W) COB (90-277 VAC) 

The California Light Works Solar System 275 LED Fixture is the most advanced fixture of the products listed as it incorporates a unique fully programmable spectrum and controller used to promote important cannabis characteristics pertaining to specific growth stage as well as optimize the yields of the cannabis being cultivated automatically.  

The fixture’s features are incredibly broad with the ability to program by the day, week, month, season & even strain as well as the ability to produce smooth transitions between growth stages. The lamp is designed to be highly versatile with the ability to control up to (1000) fixtures using (1) controller as well as compatibility with most sensors and additional lighting equipment. Overall, this LED fixture is ideally suited for growers who want maximum control over lighting conditions making it an ideal candidate for cannabis-based research.  

This fixture produces a lower PAR intensity equivalent to a (400W)(HID) making it more ideal for the cultivation of smaller/shorter cannabis strains (Indica | Auto-Flowering). For the cultivation of larger cannabis crops (Sativa | Hybrid) (2) Solar System 275 LEDs should be utilized. 

Fixture includes a power and communications cable; fixture controller must be purchased separately. Also includes a (5-yr) warranty which is longest term provided. As an advanced fixture this model is among the more expensive options.  

KIND K3 Series 2 – (XL450) LED Grow Fixture | (270W) (120-240 VAC) 

The Kind LED K3 Series 2 (XL450) LED Lamp is a fixture designed specifically for home growers that implements the same high-quality lighting solution used in Kind’s commercial-grade K5 LEDs to maximize the cannabis yields & quality of a small-scale Reproductive Growth operation. 

The XL450 LED is considered one of the most efficient of the fixtures listed since it utilizes a specially formulated broad (12-band) spectrum recipe that produces a PAR Efficiency  =  (2.15 umols/Watt). The XL450 LED also incorporates secondary optics which focuses the light allowing it to penetrate (200%) deeper into the canopy & resulting in greater flower density + harvest weight.  Overall, this LED fixture is ideally suited for growers who want an easy-to-use lighting solution that produces the optimal cannabis yields/quality and don’t mind paying extra capitol to reach that goal. 

This fixture produces a PAR intensity that’s more ideally suited for a (3’ x 3’) grow tent when compared to the other lamps listed. With a PPF = (580 umols/sec) the fixture can grow cannabis crops of any size or variety.  However, doesn’t have dimming capabilities and is configured to promote flowering so highly recommend restricting use to cannabis-based reproductive growth only. It can be used for vegetative growth, but is not as ideal for promoting vegetative grows and should be utilized in combination with other LED options like the Spectrum King’s Lil Mother LED Fixture discussed next.

Spectrum King Morther’s Lil Helper (140W) LED Grow Fixture | (110-277 VAC) 

The Spectrum King Mother’s Lil Helper (140W) LED Lamp is designed specifically for the optimized cultivation of cannabis in a vegetative growth state. Promotes leafy growth and the overall biomass increase of vegetative cannabis using a higher ratio of blue to red light. Overall , this LED lamp is ideally suited for growers who want to utilize separate fixtures for vegetative and reproductive growth. Works very well in combination with the Kind K3 Series 2 (XL450) LED Fixture for reproductive growth.

Fixture warranty guarantees lamp to maintain 90% or better light output for (3-Yrs) of regular use and (5-Yrs) for mechanical issues.