Cheap LED Strips : A Viable Alternative

[nomad]

Ok, so I’ve been designing my lighting system for a bit now and have reached the point where I’m close to ordering and want to run my setup by some experienced minds.

I’m going for a max efficiency setup. 22 x 560mm 2700k 90cri EB3 strips in a 2.5’ x 2.5’ space. These will be for full cycle cannabis but also other high DLI plants, like peppers and whatever else I decide to grow, might even throw some microgreens around the edges. My research has led me to the conclusion that those strips have enough blue to produce the optimal blue:red ratio, and stepping up to 3000k or 3500k will only add light that is less efficient at producing fruit, and my target intensity will be enough to keep stretch in check.

My hurdle right now is choosing the appropriate and most economical driver. I’m aiming for 1000ppfd@ 500ma but want the ability to crank things up just a little bit. I’ve calc’d 204w required to hit those levels @ 8.9w, 500ma, 17.8Vf, and with 240w I can hit 1175ppfd @ 600ma, 10.9w, 18.2Vf.

I figured I will run a 2Sx11P array.
XLG’s are quite a bit cheaper than HLG, but seeing as I am going for max efficiency I am fine bucking up for the HLG’s. I’m taking all my specs off Teknik’s testing sheets for the EB3 slim 560mm 2700k because from what I understand they will be the same. The HLG-240H-36 seems to line up as the right choice for 2Sx11P. For the full 240w If I math out TEKNIK’s numbers, I would need ~6.6a to run them all at 600ma with a 18.2Vf, which is right under the 6.7a max of that driver. But what if by chance @600ma the strips ran down below 17.9Vf?, that would draw JUST over 6.7a. What would happen then? I just need clarification on how my setup would run on that driver, because it seems to be JUST the perfect spec to do what I want. 500ma normally, with the ability for a bump up if wanted.

Second question, is there an XLG that would also allow this? I am very unclear on how those drivers run and there is no LedGardener videos on them to clarify. XLG-240-H-ab? If i understand correctly, two strips together would only give me around 5050ma max @ 36.4Vf?

Thanks!

[nomad]

I just realized the hlg-240h-36AB isn’t in stock anywhere in the world.
I need PWM dimming. If I try to run a type B, the ~36.4Vf is going to be
just over the CC range of the driver(36v)… What will happen then ? Bad things I take it…

[Mr.Sparkle]

Couple quick points, most strips in my experience run lower voltages than listed as they are sorta obligated to list higher rated figures or max averages for consumption, so a rated 19.4v may be a 19.2 in your setup also the temp of the strips changes that too.

HLG are typically beefy enough that they the can be over driven 10-15% so your couple extra mA won’t be an issue.

XLG operate in a spectrum so say running at 36.4v the chart below indicates you will still be in its operation window maxing at 6.6ish amps at that voltage with the current max being set by the IO pot on those drivers.

Look into the F90 strips, higher efficiencies at equal cri’s with a red spike comparably.

Also consider and to me this is a big one, even if running for pure efficiency will you easily be able to diagnose and observe any issues under 2700k light vs something more neutral, very likely no where near as well , and side thing if your into taking pictures for yourself it also mess with color accuracy in those photos.

And last commercial options are at the point now where you can get off the shelf plug and play options that achieve efficiencies that will be at or better than straight one color strips due to red/far red augmentation and par availability of that and assuming they’re using good chips, those options are getting down in price point where unless needing to build something specific for ones grow area they are something to really consider.

And welcome to the forums

[ChronicMcBudz]

@Mr.Sparkle

commercial options

It’s amazing how far technology can go in just a few years!

[nomad]

Thanks Mr.Sparkle! Was hoping you’d chime in.
The XLG looks like the ticket here, just need to confirm the strips and I’m pulling the trigger. Thanks for the clarification on how it runs.

The commercial options are good indeed, but I can still build a far more efficient light for less money.

I’ve looked at the F90’s… and while they’re more efficient, I’m not a fan of the spectrum.

Studies say HPS or very red LED spectrum produces the most flower… no more than 1:5 blue to red. I know a few people here have done full cycle on 2700 90CRI EB3’s. Can anyone provide feedback on how that went?

[nube]

Hey, welcome to Overgrow @nomad.

If you need plants to stay short, using an LED with a little more blue might be helpful. But that’s the only reason to go with a higher color temp (and more blue photons) in any application - to keep veg growth compact. And, if you are significantly height limited, I’d agree with @Mr.Sparkle that a midrange commercial strip option might be best.

But, if you have enough vertical space, plan to top and train (like with a SCROG), or just want the fastest growth and bulkiest flowers, going with the 2700k 90cri Blux EB3 is a smart move. The 2700k 90cri are in the right range Bugbee’s mentioned for best veg and flower growth: 12% or less blue, 5-15% far red, and red dominated output while still having enough green for good color with which to diagnose issues/pests. Having used mine to veg and flower under several cycles now, they’re great. Here’s the most recent harvest under them (4 different plants, grown 100% organically in recycled dirt):

Because our eyes are decent at white balancing, that pic’s pretty close to what it looked like in person, though cameras will need to adjust the white balance to get the pics to turn out right. The 2700k color temp doesn’t represent a problem to view in practice - it’s actually a really pleasant light to work with due to the 90cri rating (92.5cri as measured by LED TEKNIK). And, as you said, you can leverage light intensity to control stretch, though stretch after flip is mostly genetic.

Also, I agree that the F90, while good for efficiency, is not a proven spectrum to grow under because of the weird spike - an assertion which Bugbee actually agreed with in one of his latest videos. I would have to see independent lab analysis of those before giving them a shot. Even then, please remember that theorycrafting is NOT real world. I bought a couple Gen3 Blux Thrive 98cri 3000k strips a few months back for a home lighting application and, though the spectrum and color rendering index seem great on paper, because it’s so greenish/blueish tinted in real life, I don’t like the visual color at ALL for home lighting applications when compared to 2700k 90cri EB3 or even 3000k 80cri.

Lastly, I would personally go HLG instead of XLG. I’ve read more reports of the latter dying or having problems when running close to or exceeding specs, and I don’t think it’s worth it to save a few bucks. But that’s just me. You may want to bump up to the -42 version to cover your voltage requirements, and also for driver availability. The AB versions are often hard to get.

Hope it all works out! Let us know if you have any questions.

[nomad]

Hey Nube, thanks for the reply! Was hoping you’d chime in as well

Glad to hear the positive feedback on the 2700k. I have no height constraints so I think I’m on the right track.

You’ve heard bad reports on the XLG’s? Damn… the HLG 42 doesn’t provide enough current for my setup… the XLG seems almost perfect.

[BirD]

DIY LED Strip Build Designs for Samsung H-Series, F-Series, Q-Series, and...

So it’s around 300$ for a 2x4

[Tejas]

I used their 2x4 design using 2’ Bridgelux and very happy with the results. I found it unnecessary to use the heat sink material because the leds run cool.

[smokenhike]

Wish I went Bridgelux. My first light was the 2x4 build with 2’ LT-F564Bs and heatsinks. Good light but easy to burn plants under the center. Would’ve been better with less dense strips I think. The sinks are heavy too.

It’s a veg light now. Redid it after the driver died with 2 strips and a HLG-120H-C1400B. I’d probably put it back to 4 strips if I could find another HLG-240H-48B.

[nube]

This is worth watching to the end and taking notes, as it summarizes the current state of the art for weed lighting:

Best Grow Lighting for Cannabis with Dr Bruce Bugbee | Far red ePAR

Some takeaways from this interview, keeping in mind that Bugbee’s answers are informed by 7 straight years of university-funded cannabis research:

• 2-10% blue photons is optimal across the whole weed plant lifecycle (use less blue the less far red you have). Most current LEDs have way too much blue

• There are no cannabinoid or terp increases found from using more blue or UV, and they’ve tested it dozens of ways with UVA, UVB and violet but can find no gains at all

• Green photons are great for plants, but not safe during night cycle - weed can get photoperiod disrupted by as little as 3x the brightness of the full moon

• Red photons do not encourage stretch in veg, but far red does…mitigated by blue and high ppfd (he’s previously noted that stretch after flip to flower is mostly driven by genetics, not spectrum)

• 10-20% far red photons is optimal (use less far red the less blue you have). Most LEDs have way too little far red

• Far red is really good for early veg growth (filling in spaces, makes plants grow wide) and flower development, not as good during late veg unless mitigated by enough blue

• Neither far red nor deep red speed up flowering or put plants to sleep faster, both are popular myths not supported in any research findings, and they’ve tried many experiments to test this

• Weed can take 1000ppfd as a seedling, but any more than that requires CO2 supp
  (no more than 43 dli for veg or flower, in general, unless you’ve got optimal everything)

• Weed leaf CO2 saturation is 1200ppm and it can’t use higher than that, but at least CO2 is cheap…cuz it makes a difference!

• Weed supplemented at 1200ppm CO2 has 30%+ faster growth if everything else is optimal, and their general rule is 50% faster growth = 30% greater yields (20% more stem growth, harvest index goes down), so CO2 supplementation makes a huge difference in yield for the cost

• cannabis cannot use 24hr light, and it becomes less efficient with long photoperiods after 18hrs, and benefits from a break of 4-6hrs during veg

I hope this information helps people use and recommend better LEDs for lighting builds.

[Gpaw]

Great post… Thanks!

Cheers
G

[zavorotnuck]

Does anyone know how to secure the pins so they don’t fall off? Seems like i need resolder all pins another method so that the wires do not stick out. The wires are single and tough… Can sealant, varnish or glue help impruve situation with small contacts space?

[Tejas]

That looks like a cold solder joint. Whee the lights working before the wire fell off?

[zavorotnuck]

@Tejas Lamp was work Inside my box. ShIt was happen when i relocate my lamp.

[Tejas]

Just solder the wire back onto the contact. If it’s soldered correctly, it won’t come off.

[Shadey]

You should put some silicone sealant over those soldered bare wires to stop yourself from getting a jolt when you reach underneath the light to do stuff.

[BirD]

We’re is the best place to get a this dimmer for this hlg-240-48 b
Thanks in advance

[Gpaw]

It’s typically a 100K linear pot.

Amazon…

SAUTOP 1pcs Mini DC 0/1-10V Dimmer Knob Controller Rotary Switch PWM Dimming for...

change it from “amazon.ca” to “amazon.com” for the US offerings

or search “PWM led dimmer”

Cheers
G

[BirD]

Thank you very much @Gpaw