Experience with LED marijuana grow lights?

A inquiry from a fellow grower:

I’m looking at panels of LED grow lights that emit 300W equivelance of light per panel producing light in the 430nm - 730nm range but using only a fraction of the electricity of HPS or even flourescent bulbs.

Have you worked with the LED grow lights and what have you found?

LED lights right now have no “industry standard”, especially as to how they are marketed and sold. Some companies will give you an accurate “HID wattage” equivalent, but most do not, even some of the really good manufacturers, all they give you is the “theoretical” maximum wattage. For example, if the light is made of 100 3 watt LEDs, then it would be marketed as a 300 watt LED fixture. But it is likely really only running at about 150-200 watts and it may or may not be putting out the equivalent of a 250 - 300 watt HID light. You are going to have to do a lot of research and some of these answers may not be available, even from some of the more reputable manufacturers.

I do use LEDs but I have my own custom rig and I do not build them for sale or otherwise. A good LED system can and will give you amazing results and the best bang for electric bill buck.

Maybe LEDs will give you great results per se, on electric bill, but not bang for the buck! HID lamps are so much less expensive. I have never felt like my electrice bill was out of line, at all, compared to what I yielded. JMO

Glad to see you all like them. I wish you well.

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LEDs are more efficient than HPS or MH as per watt used to lumens output, the conversion rate of electricity to pure light is more efficient in LEDs, less is converted to heat, it is simple indisputable physics, but you have to have a properly designed system. Not all manufacturers are equal.

Everyone plaease keep in mind that this is in the spirit of debate, and based on the premise of “Successful conversation”. :slight_smile:

Physics or not. I have never seen anyone prove that LEDs can outgrow HIDs. Period. I am not saying that you cannot get excellent results, but to my knowledge; HID will outproduce LED every time. My question is: What is the perfect set up, you have designed?

Ho many watts?

And; The biggee…drum roll please… What did the entire system cost? Plug to light?


However the initial investment may not be worth it though. The most credible LED systems are way over priced and in the immediate short term you won’t save enough on your electric bill. But prices are coming down rapidly and I have seen a couple of new systems that even in the short term are more affordable than the equivalent HID system.

I do not endorse any name brand on this list as specifically being any better than any other name brand out there, however this chart gives you a good idea of average of starting cost of what even the other popular and reputable brands cost and long term costs comparing all the main artificial lighting for plants:

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Great! I like that chart. It even will enlarge; So, us Blind MOfo’s can read it. :sunglasses:

I think I will post this at latewood.com

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‘wood, I’m sorry, but I have to vote with Mac’ on this one. Especially important in areas where weed is still the number one source of income for the cops, is that LED’s give off no identifiable thermal imaging footprint. I agree with all that Mac’ says above, and darned if I am not going to look into how to make my own rig. If he can do it, I can do it. I have a new Pro Grow 260 that I got for under 3 bills, because the particular model was being discontinued. I have some 10 day old’s out in the sun, and they look no different than the ones under my light. Which I find pretty impressive. I’ll post detail here later, but I think that they are a viable option, if one shops carefully. But in the end, there are so very many variables in every grow situation, that it is a matter of personal choice, personal experience. Some folks are simply growing their own medicine, others are doing it to make the mortgage payments. C’est la vie.

Now, you boys play nice… :wink:

I am the MacGyver type in so many things I do, lol, but it’s not too hard Jodie.

I started like you, got a really really good deal on a name brand system. After the warranty had run out and some LEDs had gone out, I learned how to figure out which were good and which had gone bad and how to replace them as well as building new LED “groups” or “strips” and I wanted to build for bigger and better things, I Frankenstein-ed it. Opened it up and used all the useful parts and combined them with new parts in a new housing using all the original computer like fans and added some more along with new LED strips.

As usual there are a ton of good videos on you tube:

Thank you bunches and bunches for giving me a compass heading!! It is definitely on my ‘to do’ list. Appreciate the help, Bro.


Also this for a power converter, and you can probably find these from old computers for free, so you don’t have to use a car battery if you don’t want to:
Computer Power Supply Adapter - YouTube
And this for more important information on high power LEDs:
High Power LED Tutorial #1 - How to Drive 1W and 3W LEDs from 12 Volts - YouTube

Sweet jesus, now I understand the ‘MacGyver’ handle! Perfect fit, says I.

Here is a great time laps short video of a really great home made grow light with high power 3 watt LEDs:

Mac’, you da man! Thanks for taking the time to post this. I have all those skills. Doesn’t look any more complicated than fooling around inside a computer. One question, since you’ve already done this. What about the angle of the LED’s? Are the little diode units already angled so as to maximize the coverage/overlap area? At any rate, this is definitely doable, and I am retired, so I have all day every day to do as I please.
The video is both hugely informative, and hilarious to watch, IMHO!! I have severe ADHD, with the emphasis on the ‘H’, so I really dug watching this.


Yes, the standard lens is very wide angled and is fine on it’s own at about 18" above the canopy. Some of the newer commercial LED designs are double lensed to focus more tightly the light, theory is the focus gets deeper penetration through the canopy. With a properly pruned plant, I don’t see much advantage to adding extra lenses with a rig like this.

Some other things to think about, in the video he is using a 25% blue to red ratio. 1 blue 450 nm light and 3 red 650 nm is obviously 25%. However as I said, red is more efficient or “productive” if you will, and you only need a minimum of 20% 450 nm blue, 1 blue to 4 red would work, then you could arrange the blue in the center of the 4 red in a pattern similar to the number 5 side of a pair of dice, for even distribution of both spectra. Then add groups of 5,000 K to 6,500 K full spectrum LEDs spread evenly among the other groups, which like the higher ‘K’ rated (6500 K and up) florescent lights have a cool blue white light and have extra blue light in its spectra. This way our poor human eyes can see the leaves for their beautiful green color and you add some of the lesser used spectrum for the plant’s use, as well as adding to over all lumens/flux intensity for more robust growth and tweaking up the blue ratio beyond 20%, closer to 25%.

Recent experiments show that providing plants with white LED is also viable because LED color is achieved by using multiple compounds; thus, it is possible to provide all the wavelengths required with a white LED.

Chlorophyll absorption peaks are 430 nm blue and 662 nm red for chlorophyll A, and 453 nm blue and 642 nm red for chlorophyll B. Chlorophyll B is not as abundant as chlorophyll A, and merely help in increasing the absorption range. By having abundant white LEDs, all these spectrum are fully covered as well as making it easier on our human eyes. BTW, I would always recommend wearing polycarbonate “wrap around” safety glasses under HID or high power LED lights. Polycarbonate is naturally 100% UV a/b blocking. The really cheap silver mirrored, ever so slightly gray lenses ones would also reduce glare and make it easier on your eyes

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One more thought.

So why use red and blue LEDs at all? Why shouldn’t I just use all “white” LEDs?

You could. You could go with a 5500K - 6000k white full spectrum 3 watt LED and build your light entirely with numerous of this one type of LED.

This is the reason why I use a ratio of about a one to one or slightly less, of white to colored LEDs; just enough white LED’s to make it comfortable for my eyes:

3 watts of red and 3 watt blue is not equal to 6 watts of white.

White light is approximately equal proportions of red, blue and green light (this is kind of an oversimplification but this description suits the needs of this discussion without getting overly complex). And so 6 watts of white light is really more like 2 watts of red, 2 watts of blue and 2 watts of green, and most of the green is useless to the plant.

So having mostly red and blue LEDs gives you a more pure percentage of electricity converted to photosynthesis than an all white LED system, as up to a third of the electricity/energy would be lost in creating some of the mostly useless green light.

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Another thought, as we know from all other lights, lensing is not the only way to direct the path of the light, reflectors work just as well to make sure most of the light is being directed down toward the canopy.

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Geez, Mac’, you are my muse. No way I can thank you enough for the mental stimulation you’re providing me. My overarching goal is to get to 1 gram per watt per grow as quickly as I can. You and ‘wood and Robert are stoking the flames of my creativity. Before my spinal cord damage got too bad, I used to be a hell of a Jazz guitarist. Hangin’ with you guys reminds me of the nights when I would be playing with the real monster players. Those nights were the times I progressed the fastest. Thank you, thank you, thank you for taking the time and effort to share. Very good, very positive energy.


Geez, Mac’, you are my muse. No way I can thank you enough for the mental stimulation you are providing me. My overarching goal is to get to 1 gram per watt per grow as quickly as I can. Whatever I choose to do, I do well, eventually. You and ‘wood and Robert are really stoking the flames of my creative processes. Before my spinal cord damage, I was a hell of a good Jazz guitar player. Hangin’ with you guys reminds me of the nights when I would find myself on stage with the real monster players. Those were the times I progressed the fastest, 'cuz I was being challenged. Thank you, thank you, thank you for taking the time and energy to share with me. Very good, very positive energy.