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Yessir, the 420h LED grow light from NextLight LED Grow Lights, is what we be talking about today. I have been using this light for a full flowering cycle now. Over that time, I have come to appreciate many aspects of this light. I wanted to harvest and sample some finished buds done with this light before I did any kind of review. I did have one small concern with the light, per its spectrum being very light on UV. The low background UV did change things a bit for me, but the resin properties came through fully expressed.
So… there I was hunting for a new LED; and I had been for months. A grower friend online who I regard as a smart, great grower, who is also a good person—wow! I know, right? A rare bird these days, LoL. Anyways, he recommended I go to NextLight and have a look at their LEDs. He gave high praise to one of their LED lights (Core) that at the time he got it was under 200 watts, and had thoroughly kicked ass in his 3’x3’ grow tent.
I went there and looked at the Core LED light he was talking about, now at around 230 watts I believe, and it looked awesome—but we all know that’s only half the story of any product—so as I inquired about the spectrum with Jarrod over at NextLight, he told me about the 420h LED light they were just releasing. The rest is history, read on…

The 420h Has Some Serious Growing Power
I had my plants ready to flower in 3-gallon containers (4 of them) when I got the 420h LED lights so graciously gifted to me in exchange for relating my experiences with them to you good peeps. The Core light I originally went there hunting had its wattage upped to a 230-watt full spectrum LED. After hearing about a new 420-watt LED just about to be released, the 420h, I opted to give that one a test drive. I have secretly always wanted to run a 400-watt LED in my 3×3 Gorilla Grow Tents.
The growth rates were off the chain, truly. The plants outpaced not only my 300-watt current LED growing lights, but also outpaced my beloved 400-watt Eye Blue Hortilux HID MH lamps I normally use during winter to flower with. Not by a little bit either. By a lot. I was growing some varieties of cannabis I am very familiar with, so I got a real good read on differences when using these new 420h lights.
Time for a Bit of Cannabis Porn Under 420h LED Lighting
These lights are large for tent sized LED lights. The 420h measures about 25” square. In a 3×3 tent that is a perfecto fit—in my Gorilla 3×3 tents, I should clarify, as some 3×3 tents vary a bit in their specific measurements. But the best part about that large footprint light source, is the secondary growth.
Secondary Growth Impacts Using the 420h LED
This is where the rubber meets the road, so to speak. Not only do I think 400-watts is perfect wattage for 3×3 tents, as I got my best results before this with a 400-watt HID Eye Blue. But now I also am a big fat believer in the 25” square footprint light sourcing of 400-watts. My cola/bud size on my mains was about equal, to slightly larger, than I would have seen from my 400-watt HID lights. However, all the secondary bud growth, all those buds just below the most intense light, using the 420h were way-way up, yield- and maturity-wise. So, per plant, my yields were not only about 15%+ larger, but also had properly matured resin expressions for primo smoking enjoyment throughout. Uber potent like they should be.

More Subtle, Cool Thangs, Regarding This 420-Watt LED
- Smart Hangers: I have yet to use an LED that I thought had highly functional hangers. They are always too complex, allowing too much distance from the tent roof to the lights. These baybees have the simple answer (see above photo), it’s simple, strong, and short; noice! Good job guys ????
- Temperatures: During normal operations during flowering, with plant tops running about 82 to 85 deg. F. the top of my lights’ (housing) hits 103 degrees to the touch. In my tents they run, not surprisingly, about 25% hotter than my previous 300-watt LED lights. But much-much cooler than my 400-watt HID lights. They should be just warm enough for winter as well.
- Reliability: On my electrical grid I lucked out and happen to be on a priority basis; due to my proximity to a certain building. But my power goes off like at least a few times per month. It almost always comes right back on, but still, I have seen this stuff mess up lights before. Flying colors there. Lights had no problems.
- Well Built: When this light is in your hands, it feels good, it looks good; highly functional and elegant design.
- Full Term Light: These lights are dimmable. I confess I saw this feature as basically useless until Jarrod pointed out hardening off clones—brick wall falls on Rev’s head—D’Oh! Of course. Making this a true full-term lighting answer. I use the dimming for temperature control on super-hot days as well. Works like a charm.

Growing and Flowering with the 420h Full Spectrum Lights
Using this new 420h reminds me of flowering with HPS (high pressure sodium) lights in one way—less nitrogen needed overall, and especially during the second half of flowering. When I say “less” I mean compared to flowering with the Eye Blue 400-watt HID MH (metal halide) lighting. This new LED runs a color temperature of 4,000 kelvins. The sun runs at about 5,500 kelvins, FYI. Apparently, that is close enough for rock and roll; judging by the final results. Which are stellar gooey deadly and stinky buds.
I never observed any problems the plants had regarding nutrient processing at all. Pretty sure I would have noticed too, given the fact I grow consistently all-naturally, and I was growing plants I have flowered under several different spectrums/kelvins/wattages prior.

Afterword
The 420h LED grow light is my new top-dog favorite light for reals, like ever. They run right around $600 bucks, and I think they are well worth that price, with at least a 5-year lifespan, with a warranty and great customer service. I know I must sound like an Advert for Nextlight LoL, but no bullshit, it rocks that hard.
If you want to spend less and still get a hella bang for your buck, check out the Core series of LED lighting over at NextLight. Less wattage, less price, but according to a pretty reliable source or two, the Core lights work wicked good, especially in tents.
Swing by Kingdom Organic Seeds and grab some stellar genetics baybee! Check out another Rev article if you like: Mulching Your Cannabis Plants for Microbes.
That’s it for me today ladies and germs. See ya all back here next Tuesday for another adventure down some kind of cannabis growing path, heh heh. Happy trails and L8r G8rs.
-REv ????
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I'm The Rev, and I have been with SKUNK for about a decade now. I hail from Southern California, spent mucho time in Northern California, and now reside in Southern Oregon; always coastal. I am an all natural style cannabis grower and I have written a couple books on the subject - check out True Living Organics 2nd Edition on Amazon - I have been growing for over 45 years, and I have been breeding cannabis for over 30 years. Check out kingdomorganicseeds.com to see some exotic selections. Growing connoisseur cannabis is what I teach mostly, growing it in living soil without using liquid organic nutrients to feed the plant. I am also a highly skilled synthetics grower, hydroponics, aeroponics, DWC/SWC/NFT, Ebb and Flow, and soilless, but I cringe when smoking synthetic grown herbs, so for the last 15 years or so I preach the artisan style of all natural growing, specializing in container growing. Cheers and welcome aboard.