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Theory on LEDs - Why they need CFLs to perform

Discussion in 'Growing Marijuana Indoors' started by Syrious, Aug 21, 2009.

  1. #1 Syrious, Aug 21, 2009
    Last edited by a moderator: Aug 21, 2009
    So, I've been really thinking about this whole LED thing lately. Why are so many people having such different results? Why do the CFL + LED grows do better than the 100% LED grows?

    My first thought was that the CFLs must be doing all the work, since I had seen so many bad grows that used only LED lights. But after comparing yield (grams per watt), I noticed that LED + CFL were also out performing CFLs by themselves, watt for watt.

    So why are LEDs bad by themselves? Well, I got really high earlier and thought about it, and it actually started making sense.

    Think about plants in terms of what plants are, a living organism pre-wired to survive and thrive given the conditions. Their DNA has given them traits to detect and grow towards lights. That's why plants will always lean towards the light, even after you bend/pull/train them.

    So, we know plants can at least sense light... not only that, they can sense WHERE the light comes from!!! That's how they can lean towards light. One of LED lights' biggest problems is plants stretching straight to the LED lamp, rather than bushing out, thus hurting yield. But why?

    To explain this, I made a couple pictures in MS Paint (still kinda high, but bare with me, this is good stuff!). Notice the first picture, it shows the light spread emitted by both LED and CFL lights. Now pretend you are a plant, you are completely blind BUT you can FEEL light. If you want to grow towards the light, where are you going to grow? This is displayed by picture 2. Notice the arrows actually do mimic the pattern of growth seen from both types of lights, PLANTS GROW TOWARDS LIGHT. White light from HPS and CFL is emitted in every direction and fans out rapidly. HPS is simply more intense than CFLs.

    If a plant feels light from everywhere, it'll grow everywhere; but, if it feels very intense light from a single source, it's going to grow to that source. That is why LEDs can claim 400w/600w equivalence during VEGETATIVE growth, the plant is so small, it is only going up anyways.

    (Continue on next post)

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  2. #2 Syrious, Aug 21, 2009
    Last edited by a moderator: Aug 21, 2009

    So what happens when CFLs and LEDs are used together?
    The spread of light from the CFLs make the plant bush more, creating more surface area to absorb light. Then, the intensity and spectrum specific light from the LED promotes extremely healthy and fairly rapid growth.

    Can LED+CFL out perform HPS?
    Well, the jury is actually still out on that one. There have been results that show yields as high as 1g dry bud per 1 watt used. I'm actually doing a LED+CFL grow myself right now and am, so far, fairly pleased with the progress. Right now, I'm going to say stick with HPS for big yield if you have the right area to grow and the right cooling to keep heat down.

    When should I consider LED + CFL for my grow?

    If you have a relatively small area that you can't get very good ventalation to, this would be a situation in which this combo might be ideal. I'm still trying to see how close to HPS this setup can get. It's not equivilant yet, but if HPS is not an option, I believe this is the next best.


    So, I can't post a "theory" topic without posing a theory. I consider it's more of a hypothesis, rather than a theory, but here it is.

    First, I want people to FORGET all the false claims, 90w ufo beats 400w hps blah blah blah. What about 90w ufo and 2x30w cfls vs a 150w hps? Or 300w LED with 3x 100w cfls vs a 600w HPS.

    Now, I know LEDs are all about saving electricity, but I think that's horse shit. You can't get something for nothing. To grow something, you need to supply it with energy, no 90w fixture is going to supply a plant with as much energy as a 400w light. But, LED light is specially designed to use the most utilized spectrum of light for plants. So, is it a stretch to assume that 400w of LED/cfl might rival 400w hps with less heat generated?

    It is my belief that when there is an ideal combination of both CFL and LED light, that this setup can either match or out-perform HPS lighting. Now, whether that is 1w LED per 1w CFL in a 50/50 setup, or is it 1/2w to 1w, or vise versa. There must be some ideal combination, the trick is figuring out whether it's more LED light, or more CFL light that makes the combination work.
  3. (Space reserved for any additional findings and pictures of my finished test grow.)
  4. oh man i know someone who would absoluetly eat this thread up with his trying to sell his "best LED lights on the market" because he claims they give better coverage area. Ill let him know about this

  5. I think the problem with LED is that the technology is trying not to waste light at all (which is a great idea, don't get me wrong); but, LED lights have such a concentrated light point that plants don't bush out, mainly because there is no light outside the LED coverage area.
  6. #6 Hydro-Grow-LED, Aug 22, 2009
    Last edited by a moderator: Aug 22, 2009
    The reason why people are having such varied results, is that there are hundreds of slightly different LED grow lights out there, each using their own specific blend of light, and intensities. Most companies haven't figured out yet, how to create a LED light that's really able to rival a 400W or 1000W HID. Sure, they can provide similar, or equal growth in the area directly underneath their unit, but they rate their lights for such huge coverage areas, that there's no way it's possible for them to compete in the same area as a comparable HID. To put it simply, companies like to make a lot of bogus claims, without backing it up with proof, or reasoning.

    Take ProSource for example (I like picking on these guys, because they tried talking shit in another thread), they give you a 350W LED that is supposed to be equivalent to a 1000W. The entire panel (not just the LED board area) measures 19" x 12.5", and they claim it can cover 4' x 6' "core saturation", with a 6' x 8' coverage area. To me, this sounds RIDICULOUS. Have you ever seen a 1000W hood at 19" x 12.5"? No offense, but did everyone forget about maximum yield, or watt/square foot with HID? Would you run a 1000W HID over 24 square feet, or 48 square feet of space? Of course not, as it would only give you 21 - 42W per square foot, which is barely enough for an amateur grower. A more realistic coverage area for a 1000W light is, 4' x 2' (8 square feet), giving you 125W per square foot.

    Another thing to consider, is that LED's are not like a HID at all. They operate on a completely different principle, as HID's are hundreds, to a thousand watts in a single bulb, and LED's are a bunch of 1W light sources. A 1W Light source lacks the ability to carry light energy over long distances, but according to the information above, our competitor's overlook this fact. They give you a wide viewing angle (meaning that their 1W LED is made to spread over a large area), which reduces the intensity of the light emitted, as it has far more area to cover. Using a 120 Degree lens, our competitors send the light outward, from their small 19" x 12.5" units, to try and carry light energy to the edge of your grow space. This lacks efficiency, obviously, since 120 degree is a less intense light source, 1W LED's can't carry light energy over long distances, and they try to make it travel to the far reaches of your room! To put it plainly, these companies are just after a quick buck, not advancing LED technology.

    I take a completely different approach, which gives you a stand alone product, capable of outproducing a comparable HID, in the same general coverage area. In order to do this, you first have to start out with the correct NM LED's, and the precise ratios at which plants absorb them, for the best quality light. After you've nailed that down, it's all about intensity and spacing. Let's go back to the 1000W comparable 350W LED light above. It crams 350W of LED into a 19" x 12.5" grow space, and claims equal coverage to a 1000W. Instead of cramming all of your LED's in a small space, why not space them out on your board, and let their light blend together? If you space your LED's out, they will occupy a larger area, therefore giving you a larger coverage area, and a more equal spread vs widening the viewing angle to achieve more coverage. In my lights, I do just that. I space the LED's out on the board, and increase the viewing angle to 60 degrees. This makes sure that all the light goes down into your canopy, instead of out towards your walls. Our 126W unit occupies the same area as our competitor's 350W, meaning that you can space 3 of our units out equally, over the same area, at nearly the same wattage, creating a much more even spread of light vs a single, central light source. 3 of our 126W units, occupy a space of 19" x 37.5", and provide better results, and equal coverage to a 1000W HID. There is absolutely no need to use any type of supplemental lighting, with our LED's.



    I'm currently doing grow tests that you might find interesting on grasscity, and on my website. I list a lot of good information on my site that you might want to read, for hopefully a better understanding of why everyone else behind.
    • Like Like x 1
  7. Again Flo, I'm a woman. ;)

  8. fucking A ..... I knew that too. :eek: Im sorry Cammie
  9. #9 Rumpleforeskin, Aug 22, 2009
    Last edited by a moderator: Aug 22, 2009
    Hydro-Grow-LED statements are a bit closer to real facts then 99.9% of the BS I hear from other LED threads (great job). Only thing I had issues with is what you said a typical 1000 Watt HID would be used on. You said it would be best used on a 2x4 foot space. Most commercial grow ops use 1000 Watt HIDs over 4x8 foot tables (standard sheet of plywood). My grow is about 2x4 foot and I use a 400 HID that is a bit overkill for the space (works great).

    I have heard this before. "Show me the money" don't just take it from the guys and gals here. Big claims with no real life results. Don't trust a word a sales person has to say about LEDs.

    We have a chart for the optimal distance your plant's tops should be from the HID bulb. I would love to see LEDs come up with the same chart, but I don't think they can (or will). How far can your tops be away from the bulb/bulbs and still be 100% effective. I have a feeling it is a few inches. Most LED plants look light starved to me (including Hydro-Grow-LED plants) and grow to a fraction of their potential. Look at the best LED grows on the web, notice most have few branches and big tops (big in comparison). How many 5 or 6 foot bushes with heavy branches have you seen grown with LEDs?

    Syrious has it right, you need to stick something below the tops to get light coverage. When your done adding a ring of CFLs around your plants you can tell me the advantages of LEDs again.
  10. " A more realistic coverage area for a 1000W light is, 4' x 2' (8 square feet), giving you 125W per square foot. "

    4000 watts over a 4x8 I know your LED's must be making KUSH out of Skunk weed....I will gladly be proven wrong and take you up on any challenge concerning your LED's though!
  11. Using a 1000W over a 4' x 8' table, results in 31W per square foot. This may be fine for "commercial" growers, as you put it, but it's not fine for a professional. It's widely acknowledged, that for maximum yield using HID, you should have at minimum 50w per square foot. Personally, I used 2, 1000W units over a 2' x 4' table, and the yields were astounding compared to simply 1, 1000W per table. So can you have good results using a 1000W over such a huge area, sure, but your results would be a lot better per plant, if you upped your lighting. With me, I'm all about yield, and not about growing tons and tons of plants in a big area. I'm the type of grower who likes to produce a half pound per 2.5' tall plant, after 4-5 weeks of veg, vs 1-2 oz on 8 plants, spread over a larger area.

    Who's we, and where's the chart? With LED's, we have Lux charts, which are a bit different. Also, your chart would vary depending on whether or not a person is using a vented hood, glass on their reflector, a reflector at all, etc... our charts don't vary. As far as the distance from the top of your plants, I wouldn't go higher than 18. I personally use my units within 6-12" for optimum results. This allows the rest of the light to be able to penetrate downwards through the canopy, where it is still highly effective. Our plants are not starved in the least bit with LED, and I have no idea where you're making such baseless accusations. I'm currently doing a 400W MH vs a 126W unit, and the tomatoes under LED are growing at nearly twice the rate, with zero stress. The only plants starved, are the ones under MH. As far as 5-6' bushes, I bet you 80% of the people on this forum, don't grow em. Most people use the SOG or SrOG method, and keep their plants under 3'. If you needed a LED to be able to drive a plant that tall, you would use our 30 degree angle instead of the 60. Also, please keep in mind that when looking at other LED grows on the web, they are using underdeveloped tech.

    Hmm, the LED's I use penetrate through my plants, and get plenty of light down to my grow tray, without the assistance of a low-power CFL. Seriously, if I did a grow test with 100W LED vs 100W CFL, the CFL would look like you were trying to use a desk lamp to grow your plants. I used HID for growing, not CFL...they're too underpowered for the growth you get. Time = money, and with CFL, there's too much waiting for your plants to grow.
  12. Nah, I used 4,000W over 2, 4' x 2' grow trays (4' x 4'). I was running split spectrum (HPS/MH) before switching to LED. What challenge is that? Adding in a 20W CFL tube with 1 LED light, and in the other side, adding an extra 20W of LED? Cause I can tell you already, that if you add a CFL to our LED, and test it against the LED without CFL, of course it's going to produce more, as it has more light availability. If you're testing the CFL against extra LED though, it will lose by a long shot.
  13. As a total noob I just wanna agree with Syrious, I think he's hit the nail on the head.

    Until the geneticists develop a strain that is wired to a very, very narrow part of the light spectrum, and my physics isn't strong enough to say what that is, it's obvious that the strains we have at the moment will definitely grow better when the light is from sources that give a better spread of either veg or flowering light.
    If you think about it the genes have to make plants that grow under bright sun or cloudy skies, so the light will differ NATURALLY.
    Therefore it seems to me that at the moment the best growing light setup will be the one that mimics nature most closely by having this relatively wider spectrum.

  14. Who do you think is growing commercial? Rookies? The commercial grower need the plants to make max yeild in the shortest amount of time. How are they not pros. Every operation I have worked or toured is manned by professional growers. So they are wrong and should be growing on skinny tables with "break the bank" LEDs?

    Let me show you some pictures of my 2' x 4' grow operation (just happens to be that size).

    I use a 400W HID, veg for 10 days and flower for 60. I dont grow a bunch of small plants, I grow two 4.5' tall plants at a time and have topped a pound from a single harvest. I have a few week to week journals if you want to see the progress or doubt the numbers.

    Now I am doing it all wrong. I should listen to you and cram a 1000W lamp into that space to get more yeild? Or better yet sell one of my cars to pay for a fantastic LED grow light.

    She can't talk about 400W HID lamps (no power savings advantage)

    The reason you dont want to compare your lamp to my 400W lamp is sales. It has to out do a 1000W lamp or why would any knucklehead ever buy one? Same wattage as mine and mine is one tenth the cost (or more).

    I have a 2x4 foot grow space. your telling me I can do better with your LED lamp? Or my 400W is not working well?

    Let me show you a single plant I got ten ounces from using my shitty 400W lamp. 10 days veg time:

    That plant after harvest and dried:

    This is the kind of proof we need to see. Show the harvest, show the monster 7' tall tree grown indoors, show the big fat bud two people have trouble lifting, but don't show any more stupid rainbow graphs.

    Hey and don't forget about the heat signature tactic. My 400W lamps is making my broom closet radiate for miles in a glow that is unique to a 400W HID grow lamp.:eek:

    Your overpriced LED lamp can't out perform a 400W HID. And to compare it to a 1000W is laughable. The debate should be: What works better CFLs or LEDs.
    I'm with Syrious and say if you have to use them use the combo.

    No one (and I mean it) wants LEDs to work better then HIDs more then me. I want nothing more then to improve my lamp, use less power, and make no heat. But all I have seen is lights starved plants.

    Nuff talk, lets see the buds:
    • Like Like x 3
  15. thats what the fuck i'm talking about
    i have looked at your journals and they are very impressive.

    LEDS just aren't nearly there yet maybe someday but not today i think i'll stick with my HID
  16. I have an open mind, so i tell you what I will do Hydro-Grow-LED. You send me the LED unit and I will plug it in for a full cycle. I only need to provide a small amount of medical marijuana now, so the reduction won't kill me.

    If you want to show the growers that the LED light can give me the same or better results, send me the unit and I will sacrifice my normal yeild in the name of science. I will post the results on any or all my threads. Look at the traffice at the bubble bucket thread if you question weather or not it would be worth while.

    My grow is the same time after time (same mom same nutrients).

    Your chance to back up the wild claims for free. I don't think you can get Ed Rosenthal to do it. You will have to settle for me.;)
  17. any led company would be stupied to not take him up on this offer. you have a grower that pulls the best yeild from a 400w i have seen, and why wouldnt you want to have him test out ur product. a suthor is just a author, he writes books about other people grows. and it would be a shit load cheaper for Rumpleforeskin to do it.. so what you give out a free light? witch will boost ur sales like crazy. better take him on this offer or i will make some phone calls and have it a done deal on monday for him. i would love him to do a led grow.. it cant get any better then this.
    • Like Like x 1
  18. I second the motion.
  19. #19 Hydro-Grow-LED, Aug 23, 2009
    Last edited by a moderator: Aug 23, 2009
    This plant was 2.5' tall and yielded 8 oz's. The bud you're looking at, weighed 31grams (although the pic was taken a week before harvest). Did I mention, this was one of 20 plants in my 4' x 4' grow area? Yup, all 20 competing for the same light, yet seemingly producing about 2.5 - 3lbs per thousand. At the time, I was running 3k. I run 1500ppm CO2, water chiller at 67 degrees, Advanced Nutrients, and custom aero units with a high volume oxygenation pump. So just cause you can grow a pound under a 400W, doesn't mean you're any better a grower. I advanced from 400's after my first grow, because I got serious about growing a lot of plants, not just 2-3 at a time. Anyhow, all I'm trying to get across is that you're very good Rumple, but in no way are you the god of weed growing (and neither am I, but my buds are bigger). If you want to see a 126W LED beat your 400, I'd have no problems with that. And by the way, I've spoken to Ed quite a bit, and well... don't assume

  20. #20 irishboy, Aug 23, 2009
    Last edited by a moderator: Aug 23, 2009
    so ur not going to give him a 126W to test for free? nice looking plant by the way.

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