HLG 300 V2 Quantum Board LED Grow Light – Detailed Review

Some members of the indoor growing community have recently started using Quantum Board LED grow lights. One popular brand and model in particular is Horticulture Lighting Group’s HLG 300 V2 Quantum Board LED grow light.

The HLG 300 V2 quantum board is a large, white spectrum, modern design LED grow light that effectively covers a 2 foot by 2 foot grow space.

***UPDATE – THE HLG 300 has been discontinued. Check out the HLG 600 or the Mars Hydro TSW 2000 for a comparable grow light. ***

Horticulture Lighting Group actually came up with the “quantum board” grow light design and started the trend among the indoor plant growing community.

In this detailed review we plan to answer all your questions about this grow light.

HLG 300 V2 Quantum Board LED Grow Light

Free Grow Guide to Download

This is a mid-range quantum board LED grow light from Horticulture Lighting Group’s product lineup.

The light has 2 circuit boards, each containing 288 (576 total) Samsung LM301B diodes. Samsung is known to produce top-shelf LED quality, so you won’t have to worry if you decide to go with this quantum board grow light. The boards are placed on a larger aluminum panel with a dimmable Meanwell driver on the opposite side.

The HLG 300 V2 measures in at 18″ x 20″ x 3″.  It comes with a 120v plug, so you’ll need a 120V to 240V Adapter if your country uses 240v.

The Horticulture Lighting Group 300 V2 is ETL certified, meaning it meets North American safety standards.

How is the HLG 300 V2 Quantum Board Grow Light different from other LED grow lights?

Quantum board grow light samsung lm301bIf you’re used to using regular or COB LED grow lights, the quantum board design is more bare-bones. You’ll notice there are no fans on the design. There’s also no “reflector” or glass magnifying lens on this design.

One of the biggest differences with the quantum board led grow light design is the light color. Many people appreciate this feature because it’s easier on the eyes (That doesn’t mean it’s safe to look directly at the light board. Don’t stare directly at the LED light board).

The HLG 300 V2 quantum board LED grow light will draw 285 watts from your wall at maximum power.

The Meanwell driver has a rubber stopper on the “Output” side, you can remove the rubber stopper and adjust the light intensity with a Philips screw driver. You can dim the HLG 300 V2 down by 50%, bringing it down to 120 watts of power consumption.

Free Grow Guide to Download

I suppose it depends which grow light models you compare, but I compared the HLG 300 V2 to 3 very popular non-quantum LED grow lights and the power consumption is almost exactly the same.

Full White Spectrum & Uniform PPFD:

This light features a full white spectrum. You can check the spectral charts for each version here: 3000k | 4000k. A lot of people focus on red and blue wavelengths for plant growing, which is great. But studies have shown that white light spectrum (yellow, orange and green wavelengths) added to red and blue wavelengths are more beneficial than red and blue alone.¹

A second study showed tomato plants yielded 12-16% more when white light spectrum was added to red and blue spectrum.²

Don’t worry, white spectrum lights actually include blue and red wavelengths, so you aren’t losing those wavelengths. You’re simply gaining yellow, orange and green wavelengths along with it. This would explain recent the shift of more sophisticated growers to high quality white spectrum grow lights like the HLG grow lights.

If I had to pick between the 3000k and 4000k model I’d take the 4000k based on the spectrum, but they’re both just fine.

Another big difference with Quantum Board LED grow lights is the uniform photosynthetic photon flux density (PPFD) that doesn’t fade dramatically when you measure further from the center of the PPFD chart, which is the case for many “regular” LED grow lights.

To understand better, let’s look at PPFD charts for the HLG 300 V2 quantum board vs two other COB LED grow lights:

ppfd chart

ppfd chart

hlg 300 v2 ppfd

The top chart is from a 450 watt COB LED grow light. The middle chart is a 500 watt COB LED grow light. The bottom chart is the HLG 300 V2. I’m asking you to look at the far side measurements on each chart.

The difference is the Horticulture Lighting Group 300 V2 maintains a considerably higher (and usable intensity) PPFD at the edges, while the first two COB LEDs’ PPFD dropped off considerably when measuring 3 feet from center.

Coverage Area:

While we’re on the subject of PPFD, the HLG 300 provides sufficient PPFD to get your marijuana (or other) plants from vegetation to flowering. The HLG 300 V2 PPFD chart above contains measurements in an open grow space.

Horticulture Lighting Group also posted PPFD readings from inside a 3×3 grow tent where the readings were considerably stronger. So for an open grow space I’d recommend this light for 2×2 foot coverage. Inside a grow tent you can get 3×3 feet covered comfortably.

You can also consider the HLG 550 V2 if you want stronger light in your 4×4 foot space.

Heat (or not):

The HLG 300 V2 doesn’t feature cooling fans or heat sink on the design. That’s because it doesn’t need them. One owner reported their HLG 300 V2 doesn’t get hot at all, only gets warm. Another person said they don’t have any circulation beyond normal airflow from a ceiling fan, and the light runs perfectly cool.


The HLG 300 is a pretty decent light if you’ve got a 3×3 grow tent:

HLG 300 Review Horticulture Lighting Group


Warranty and User Comments:

Horticulture Lighting Group provides a 3 year warranty with this quantum board grow light. Three years is among the more generous duration warranties we typically see with grow lights.

There are a couple dozen reviews combined between Amazon and other reseller websites. A majority of the reviewers are very pleased with the HLG 300 V2. Aside from the general positive comments, many people commented on the strong brightness of the light. Someone who’s tight on space appreciated the fact they didn’t need to waste space with cooling equipment. Another person said the HLG 300s are more versatile than the larger 550 models, so they’d prefer buying two HLG 300s instead of one HLG 550.

What’s in the box:

You’ll receive one HLG 300 V2 Quantum board LED grow light, one fixture, one 120v plug, and a few 1/8″ hangers.


Save Money and Get More with a DIY Kit:

hlg diy kit

Want to save a couple bucks and get a stronger grow light simultaneously? If you’re willing to spend 30 minutes of your time assembling the grow light on your own, I highly recommend the HLG 260 watt V2 R-Spec DIY kit.

This kit uses the same 2-panels as the HLG 300 v2. It uses the same LEDs and emits the same light spectrum. The only difference is a stronger driver which increases light intensity. This kit consumes 260 watts instead of the 270 consumed by the HLG 300 v2. Assembly is straightforward, and there are assembly videos on YouTube to help you step by step if you need them.

Frequently Asked Questions:

The Amazon page shows two light spectrum options (same price) – 3000k and 4000k. Which one is better?

  • The 3000k version is sufficient for all plant growth phases, seed through harvest. The 4000k version is recommended for vegetation phase only because it produces a much higher blue light spectrum. Personally, based on both spectral charts, I’d take the 4000k if it’s available.
  • You can view the spectral charts here: 3000k | 4000k

Amazon seller is out of stock, can I buy one anywhere else for the same price?

  • Yes, Click Here to visit LED Grow Lights Depot. Many times their price is the same as Amazon, although not guaranteed. They also have incredible customer service – just like a family business.

Is the HLG 300 V2 setup complicated?

  • It’s very close to plug-and-play. No complicated setup.

What’s the recommended hanging height?

  • I would recommend 18″; Horticulture Lighting Group says 15-24″ is fine. You can adjust based on required coverage/intensity.

The Takeaway:

Is the HLG 300 V2 quantum board LED grow light a game changer for growers? A lot of people like it, but it doesn’t necessarily “blow away” regular or COB LEDs grow lights. It’s different, new, innovative, but the wheel wasn’t reinvented.

The HLG 300 V2 is a nice grow light with it’s own respective benefits. If you prefer white light over purple light, this light is for you. If you like a lean design without cooling fans, this light is for you. If you don’t mind either way, can you find a regular LED or COB LED light that’ll compete with this light on cost, spectrum and PPFD? Sure you can.

If you decide against this quantum board LED grow light for whatever reason, you can always check out our Best COB LED grow light review, or Best 1000w LED grow light review.



What Size Grow Space Is The HLG 300 Grow Light Good For?

The HLG 300 grow light is sufficient for a 3×3 foot grow space or grow tent.

What Height Do I Hang The HLG 300 Grow Light?

Every grow light needs to be hung at a different level based on a variety of factors. Read my post on grow light height for more details: Grow Light Height

What Other Grow Lights Compare To The HLG 300?

The Mars Hydro TSW 2000, Bestva 3000w and Nextlight Mega, are all close competitors of the HLG 300.


  1. 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.
  2. 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. Sharakshane, Anton. “White LED Lighting for Plants.” bioRxiv (2017).
  4. 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.
  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.
  6. He, Dongxian & Kozai, T. & Niu, Genhua & Xin, Zhang. (2019). Light-Emitting Diodes for Horticulture: Materials, Processes, Devices and Applications. 10.1007/978-3-319-99211-2_14.

Other References:

Horticulture Lighting Group


My name is Nick, and I'm a home grower who spends time writing about indoor growing tools and setups. My goal is for 420ExpertGuide to be a one stop shop for indoor growers to find the information they need.