The indoor grow light technological revolution is racing forward, and that’s great news for marijuana growers.
We’ve given you articles before about grow light gurus finally unlocking the secrets of how the electromagnetic spectrum affects cannabis plants. And we’ve highlighted grow light companies that have engineers and plant scientists on staff, making advanced LED grow lights based on new research and the latest design paradigms.
Recent tech changes in the marijuana grow light universe are a welcome alternative to the orange light of high pressure sodium, the blue light of metal halide, and the typical reddish-purple LED grow light spectrum.
What we’re looking at now is white light—a full color spectrum which to your eyes looks like the light from the sun at noon on a cloudless summer day.
Grow lights that produce this pure white light are sometimes called “quantum board full spectrum” lights. We procured test units called the Core and the Mega from a company called NextLight.
The spectral output from the Core pumps heavy doses of blue, green and red, instead of the usual grow light that has ample blue and/or red, but hardly any green or other transitional colors.
NextLight told us their 190-watt flat-array, aluminum-housed, ultra-thin, ultra-light grow light can be used from seedling or clone all the way to flower with better results than using any other type of grow lighting.
They specified a 4 foot x 4 foot (16 square feet) coverage area in grow phase and nine square feet of coverage in bloom phase, with the light placed as close as 8-12 inches from the canopy. These estimates turned out to be precisely accurate, especially if your grow space is a tent or otherwise properly light-reflected.
The manufacturer stipulates a range of 500-950 PAR (photosynthetically active radiation) at these distances. In my testing experience, the coverage area is more predictable and uniform than those numbers suggest.
My Apogee LED grow light meter showed negligible differences in PAR across the unit’s approximately 21 inch x 21 inch housing. It’s a near-perfect rectangle, and light distribution benefits from this design.
The Apogee meter is by far the most if not the only accurate and useful meter for measuring light intensity and distribution under LED grow lights.
Note that the Core is ultra-thin and very light—making it exceptionally useful in grow tents and other situations where heavier grow lights risk snapping support bars or straining motors of light movers.
Considering the unit only uses 190 watts, the PAR distribution maps provided us by the manufacturer showed better light distribution and more intensity, with far fewer hotpots and dropouts, than we’ve seen with most other LED or HID grow lights, including grow lights that cost more and use a lot more electricity.
NextLight promised that due to its use of the highly-rated, super-efficient Samsung LM561B white diodes, the light generates significantly less heat than competing lights.
This saves you money on air conditioning, and allows you to get the NextLight a lot closer to your plant canopy—a big plus in grow tents and other spaces where vertical space is limited.
NextLight promises an impressive 100,000 hours of full-intensity diode output at 77°F ambient grow room temperature. If you grow photoperiod plants using traditional 18 hours grow phase and 12 hours bloom light cycles, you get at least a decade of full-time use from the unit, if not a lot more, with no significant decrease in light intensity or spectrum quality.
From an economic perspective, this light is insanely useful. The NextLight Core retails for around $550 and lasts for at least ten years. Compare this with using HID bulbs: it can cost you $550 just to replace HID bulbs as they wear out over the course of a few seasons.
Other LED grow light brands and models offer around 35,000-45,000 hours of use before diodes wear out, but those lights cost a lot more than the NextLight Core.
Along with those economic benefits, you get efficient electricity-to-light conversion ratio. Instead of converting much of its electricity consumption into heat, like most grow lights do, the NextLight Core is far cooler, and less heat means lower air conditioning costs.
Another beneficial aspect of the NextLight design is that the light is passively vented, with no fans or other moving parts. This means no noise, no fan failures, etc.
Of course, the real test of a grow light is what it does for your plants. Our grow team tested the NextLight Core and its larger relative, the NextLight Mega, in a dozen full grow op cycles, competing it against high-end, spectrum-adjustable LED grow lights that cost a lot more.
As I mentioned earlier, we were skeptical that a white-light grow light from seedling/clone all the way to harvest could produce results as good as an adjustable LED grow light. We’ve had it drilled into our heads for decades that blue light is for grow phase and red-orange for bloom phase.
When we saw the positive results during the first test, we were impressed but still skeptical because one grow test by itself isn’t conclusive proof of anything.
But after multiple seasons using a variety of marijuana photoperiod and autoflowering marijuana genetics, we concluded that using NextLight from start to finish is an easy grow light option that produces useful results.
The 190-watt NextLight Core, especially when used in a 4 x 4 tent, is superior to Black Dog, Fluence, Gavita, Spectrum King, Iluminar, Kind, and several other LED grow light brands that suck down more electricity and cost more to purchase.
Those other grow lights cost from 40-130% more than the NextLight Core, have shorter operating lives, consume more energy, are heavier and noisier, and produce more heat than the Core.
On top of that, their effects on plants are less ideal, in some cases creating unacceptable stretch and other undesirable traits.
NextLight also offers their larger white-light LED grow light called the NextLight Mega, for large indoor spaces including commercial grow ops. The unit measures 37 x 37 inches, is just as thin as the Core but weighs much more, and provides intense high-PAR illumination for at least 35 square feet in grow phase and 25 square feet in bloom phase.
The Mega can be run with an optional dimmer for situations where height adjustment doesn’t optimize light intensity to deliver exactly the PAR dose your plants can handle.
The Core can’t be dimmed, but all you do to control PPFD intensity is use the Apogee LED-specific light meter, watch your plants’ performance and whether your leaves are suffering from LED burn, to determine the proper light-to-canopy distance for the unit, so you’re dosing your plants with just the right amount of light.
We’ve found generically that the Core is best placed 24-37 inches from seedlings or clones, and then gradually lowered as plants develop root systems and can handle more light.
In bloom phase, the unit is hung 14-26 inches from the plants, depending on the strain’s light requirements, whether the grow room has added C02, and other factors.
The Mega has to be placed further from plants and thus isn’t as useful in tents or in limited vertical space rooms as the Core is. But the Mega has the same 100,000 hours of operational life, and is a superior option to other 600-watt or 1000-watt LED brands or HID grow lights.
We’ve seen it produce better harvest weight and cannabinoid/terpenoid results than a double-ended 1000-watt HID grow light, with a fraction of the heat and cost. The Mega delivers high PPFD to at least 16 square feet of grow space, with remarkably even light distribution.
There are quality and longevity negatives related to full-spectrum quantum board grow lights, and I note that when I asked NextLight for records of cannabis grow room testing and scientific photobiology research into their lights’ efficacy, they never provided any info.
This is important, because scientists I’ve spoken to say that the “full spectrum” output of these lights isn’t optimally tuned for cannabis, and is a compromise, rather than the ideal spectrum.
For growers who are familiar with Horticulture Lighting Group quantum board grow lights, the NextLight products are similar in quality, efficacy, and price, and are most useful for lighting grow tents during grow phase.