The Best Grow Lights for a 2×4 Grow Tent – Pictures, Specs, and More
What are the best grow light options for a 2x4 grow tent? My personal recommendations are a 150w HPS grow light, the Spider Farmer SF-2000, Green Sunshine ES300, or HLG 320 watt DIY quantum board LED grow light.
The most important factors to consider when choosing a grow light for a 2x4 foot grow tent are the light intensity and uniform coverage area of the lights. If you pick the wrong grow light your plants won’t grow to their full potential. All the options I mention above meet or exceed those requirements.
When you’re done reading this, don’t forget to check out my article on choosing the right size fan for your grow tent.
Budget Choice: Hydroplanet 150 watt HPS grow light
Why am I recommending an HPS grow light as one option for your 2x4ft grow tent? I talk to growers daily and some are on a budget. This 150 watt HPS grow light from Hydroplanet represents a good 2x4 grow tent option for a few reasons:
- It’s cheap.
- The light intensity is strong enough for 2x4ft grow tents.
- Despite HPS grow lights’ reputation as heat blowers and electric hogs, this small 150 watt model doesn’t produce much heat or consume much electric due to its smaller size. It actually consumes less than the LED lights I’ll be mentioning next.
It’s not my first choice and I don’t recommend being cheap with lighting. But if you’re extra strapped for cash, 150 watts from this light will get the job done.
The one thing I’d recommend to buyers of this Hydroplanet 150w HPS grow light is to purchase a wing reflector separately instead of using the included hood style reflector. The wing style reflector will spread the light more widely across your 2x4 foot grow tent.
Aside from that, this grow light is plug and play. It comes with a 10 foot power cord and a 150 watt bulb. Hang this light 18-24 inches above your canopy and you’ll be good to go. Hang it 26-28 inches above for seedlings.
The Spider Farmer SF-2000 is a modern quantum board LED grow light. This light is rated for 2x4 feet of coverage and it uses the same LEDs and driver as HLG, but it’s priced a bit lower. The LEDs are Samsung LM301B and the driver is Mean Well -- a high quality industry standard driver.
I bought one for my 2x4 grow tent at home and it looks and performs great. It consumes 200 watts from the wall so it’s not bad with power. Take a look at the light intensity the SF-2000 provides:
The spectrum coming from the SF-2000 contains warm white (3000K), cool white (5000K) 660nm (red) and 760nm (infrared). This spectrum will grow your plants through every phase of growth.
Take a look at the buds people have grown with Spider Farmer grow lights:
These pictures are from Instagram, and you can see the hefty buds grown by Spider Farmer owners. These plants are nothing to balk at.
SF-2000 Key Specifications:
- Will flower a 2x4ft space -- larger for seedlings.
- Consumes 200 watts.
- Dimmable ballast included.
- High quality LEDs and Driver (Samsung and Mean Well).
- Best performance for the price.
Does the SF-2000 get hot?
Like all grow lights it does create some heat, but it’s manageable. Keep the air circulating, and keep the room where your 2x4 grow tent is located cool.
What height do I hang the SF-2000?
It’s safe to hang this light 18 inches during veg and flowering, and 28 inches for seedlings. If you don’t have enough space to hang the light higher, you can always dim it, but you’ll have to unscrew the driver from the board to access the dimming screw that’s on the underside of the driver.
Performance Choice: Green Sunshine ES300:
The Green Sunshine Electric Sky ES300 is a high end grow light that’s perfect for a 2x4 foot grow tent. This is a powerful grow light with a custom designed spectrum. For that, you’ll pay a premium. But it’s worth it.
The Green Sunshine Company believes most grow light spectrums don’t contain enough infrared, so the ES300 emits higher levels of infrared and red than normal.
The color breakdown is as follows: Approximately 10% blue, 25% green, 55% red, and 10% infrared. It’s a highly customized spectrum, far from the ‘typical’ blue + red combo you see on most LED grow lights.
Michigan State University ran an experiment to see how useful the inclusion of green light is for plant growth, compared to other common spectrum makeups. Not only did they find that green light *is* useful in photosynthesis, but the salvia plants grown with a majority Green/Red spectrum similar to the Green Sunshine Electric Sky ES300, actually grew 2nd tallest out of 6 different spectrum combinations.
Green Sunshine Company also says this:
With the unique high-dosage of near-infrared light, large flowers initiate sooner, vegetation grows faster, and the plant makes more efficient use of light from what is known as the Emerson Effect…
Not only is Green Sunshine very confident about their spectrum, but perhaps more importantly, the customers who’ve bought their lights swear by them. That definitely caught my attention. Growers who brought this light say it noticeably reduced the time their plant spent in the vegetative phase, and grew all around better plants.
Finally, take a look at the light intensity when it hangs in a 2x4 foot grow tent 18 inches above the canopy:That’s an impressive amount of light all across the 2x4 foot footprint. Your cannabis plants will definitely grow nicely under this grow light!
ES300 Key Specifications:
- Will flower 2x4 foot grow tent. Covers larger space for seedlings.
- Consumes 300 watts
- Includes dimming capability
- High performance in a 2x4 space
- Heat sink frame dissipates heat well
What Height to Hang The Green Sunshine ES300:
The special lenses on the ES 300 allow you to place the light very close to the plants without burning them. Even though the intensity numbers above are from the standard 18 inches, The Green Sunshine Company openly states the ability to hang the light as little as 12 to 15 inches above your canopy. That’s pretty impressive.
I’ve looked over and researched many grow lights, and I have to say I don’t know that I’ve seen a grow light with more consistently positive reviews than the Green Sunshine grow lights.
Feel free to read the reviews for yourself. Aside from the generally positive comments, growers have mentioned shortened vegetative growth phases, and better quality plants.
DIY Choice: HLG 260 Watt QB XL
If you don’t mind spending a few minutes doing a simple assembly, the HLG 260 watt QB (quantum board) is a popular choice for growers with 2x4 foot grow tents. This is the XL version, meaning the main board is extra long, in order to space out the LED boards a bit more for better light uniformity.
The HLG 260 watt quantum board is a great choice for a 2x4 space because you’re getting HLG quality and performance at a fair price. Assembling the light yourself allows them to sell the board at a cheaper price.
The coverage in a 2x4 foot grow tent is perfect, and I’ve heard from many growers who are pleased with this grow light in their 2x4 foot grow tent.
HLG 260 Watt QB XL Key Specifications:
- Flowers a 2x4 foot space.
- No Soldering required. Only screw driver and wire strippers.
- Very power efficient at 2.7 umol/Joule
- Consumes 260 watts
- Dimmable driver
- Includes hang kit
- 3500K color temperature with 660nm red (see below)
Here’s a look at the intensity when the light was tested in open air:
Keep in mind this is open air testing, so when you place the HLG 260 watt QB into your grow tent, the reflective walls will increase the light intensity even more.
The spectrum is a 3500K temperature which is generally accepted as ideal for growing cannabis in all phases of growth. The light also includes 660nm red diodes which ensure there’s enough red light for a strong flowering cycle.
The video below is for the non-XL version, but the assembly process is the same, so you get the idea:
Which of these grow lights would I personally choose for a 2x4 foot grow tent?
Growers often ask my opinion after reading my lists. My personal choice for a 2x4 foot grow tent would be either the Spider Farmer SF-2000 or the Green Sunshine ES300. Both are very good lights and I think you’ll be very satisfied with either one. The HLG is also very good but has tough competition in the SF-2000 which is priced slightly lower.
I don’t recommend the 150w HPS, but occasionally I talk to people who are on a tight budget. If that’s your case you can go with one of those.
The smallest number of watts needed to grow cannabis in a 2x4 foot grow tent is 40 watts per plant, although the best grow lights use at least 200 watts for the whole tent.
Two to three cannabis plants will fit in a 2x4 grow tent. It can vary depending how large the plants are allowed to grow.
An inline fan rated for 100 cfm to 120 cfm will be sufficient for a 2x4 grow tent.
If your grow tent is too hot, try cooling the room where the tent is located by opening a window or using an air conditioner. If the grow tent is too cold you may need to buy a space heater for the room the tent is located in.
You can control humidity in your grow tent by using a humidifier or dehumidifier.
- Chandra, Suman, Hemant Lata, Ikhlas Khan, and Mahmoud Elsohly. “Photosynthetic response of Cannabis sativa L. to variations in photosynthetic photon flux densities, temperature and CO2 conditions.” Physiology and Molecular Biology of Plants 14.4 (2009): 299-306.
3. Eichhorn Bilodeau, Samuel et al. “An Update On Plant Photobiology And Implications For Cannabis Production”. Frontiers In Plant Science, vol 10, 2019. Frontiers Media SA, doi:10.3389/fpls.2019.00296. Accessed 14 Oct 2019.
4. MARUO, Toru, et al. “Effects of Supplemental Lighting with Light-Emitting Diodes (LEDs) on Tomato Yield and Quality of Single-Truss Tomato Plants Grown at High Planting Density.” Environmental Control in Biology, Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists, 11 June 2012, https://www.jstage.jst.go.jp/article/ecb/50/1/50_63/_article.
5. Lin, K., Huang, M., Huang, W., Hsu, M., Yang, Z. and Yang, C. (2013). The effects of red, blue, and white light-emitting diodes on the growth, development, and edible quality of hydroponically grown lettuce (Lactuca sativa L. var. capitata). Scientia Horticulturae, 150, pp.86-91.