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quinton_gw

led vs. hid vs. fluros. please advise.

16 years ago

Hello. I'm new at this and just trying to figure things out. My understanding about plant lights is the following. Please correct me where I am wrong. Here goes.

The three most widely used kinds of grow lights seem to be HID, fluorescent, and LED. The strong point of LED as a grow light is that it can selectively emit the colors most efficiently used by a plant. A big problem with LEDs is that the quantity of light they emit is limited, and so its very expensive to build a big enough LED lamp to be useful as a primary grow light.

The HID, (MH, HPS), emmission spectrum is a little less well tailored to a plant's needs than the LED, but HID lights more than make up for that disadvantage by emiting a far greater quantity of light than a reasonably priced LED or a fluorescent grow lamp can. HID lights also penetrate deeper into foliage than fluorescents or leds can. HID light's disadvantage is that it creates lots of potentially damaging heat which usually has to be sucked away with a fan.

Fluorescents are nice because they burn cool enough, (like LEDs), to be able to burn very close to the tops of the plants without damage, and the bluish spectrum of some of the phosphor coatings is very good for vegetative growth. But they lack the red light plants need for flowering, and their light penetrates foliage less than HID light would. So far so good?

But why is it that HID light penetrates better? Is it because light from an HID light has more energy? A photon is a photon, isn't it? Why should an hid's photon penetrate better than any other light source's photon?

I also wonder why cold cathode, (CC), lamps aren't more popular as grow lights. CC tubes come in a very wide variety of colors, including saturated reds and blues, and can be hand bent to conform to any shape, and can be quite bright. CC lamps also burn cool like fluorescents. I'd think cold cathode grow lamps would be cheaper and better than LED lamps, and be at least as good as T5 fluorescent lamps are, and in certain grow schemes, maybe even better than HID. Yet nobody seems to talk about them. Is there some disadvantage to cold cathode lamps I haven't considered?

Thanks!

Comments (71)

  • 16 years ago
    last modified: 9 years ago

    Thanks for sharing your experience with the bulbs Paul, and Shrubs - great idea of sourcing fixtures commercially. For some reason that hadnt been at the forefront of my mind. Subconsciously I must still associate commercial fluorescents with those hideous underdriven economizers that hum and suck the life out of everyone through their eyeballs. .
    I'll sniff around and see whats out there. Have any of you looked at Sunlight supply's TEK T5 fixtures in the flesh? Are they about the best?

    http://www.sunlightsupply.com/products.cfm?sid=F5AB8624E0815D55343A4C9F81546180&c=55&sw=1

    Also, I'm wondering if Sunlight Supply actually manufactures these lamps, or if they only mark-up and market the fixtures?

    - Break -

    Ok, I did have a few moments to web search commercial fluorescents while traveling up the coast yesterday. All I could find down that avenue in a T6 setup was a sea of 6-bulb HO fixtures, no 8-bulb lamps. And all those had their ballasts mounted conventionally atop the reflector making them nearly twice as tall and more bulky. None were aluminum. None offered a choice of bulbs, and most had reflectors that didn't seem as well designed as the purpose-built grow/aquarium fixtures. Prices for the generic commercial fixtures were cheaper of course, but surprisingly by only $50-$80 dollars.
    After I've been freed from the yoke of Christmas responsibility I'll call a few commercial lighting suppliers here in the Orange County / Los Angeles area and let you guys know what I find.
    In the mean time, if anyone knows who might offer the best price on the TEK lamp described above or its generic cousin , please chime in. If all else fails that'll probably be the way I go.

    Thanks again guys, may your bulbs all burst this season -
    not your lamps! . . . I mean you gladdies :)))

    Phil

  • 16 years ago
    last modified: 9 years ago

    Oh those lying bastards. The Sunlight Supply page offers the following comparison for their wonderful T5 lights: "F40 cool white lamp: 1260 lumens per lamp". Criminal deception! For those non-spec-heads out there, even a dumbed down energy saver T8 running at 28W will put out double that and an actual full power 40W cool white will put out about three times that. But then maybe they feel the truth wouldn't sell so many expensive lights?

    In terms of the lighting technology, every single T5 system is almost identical, same electronic ballasts and same triphosphor light output. If you look really hard you can now find a few tubes with different spectrums. The efficiency of the T5HO tubes is no better than a good quality T8 or T12 but they put out a lot of light from a small tube. Feel free to source the ballasts and tubes from anywhere you want.

    The area to be careful with is the reflectors. Commercial reflectors simply aren't designed for lighting plants. But to be honest, even the reflectors on the lamps at your link don't look so fabulous to me, despite being made from German aluminium (is the periodic table somehow different in Europe?) and having a trade-marked name :) A good reflector has the tubes recessed inside it and not sticking out spraying light all over the place. A good fluorescent reflector system casts a distinct illuminated patch below it and doesn't light up the whole room. You might want to make your own.

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  • 16 years ago
    last modified: 9 years ago

    Stop mincing words, what do you really think? :)))
    I love a wallflower, especially one under artificial light - LOL!!

    Frankly, I didn't pay too much attention to the 'numbers', assuming bulbs and ballasts were off-the-shelf. I was more interested in packaging size and the reflector's suitability.

    I was just hoping someone could impart practical experience looking over the TEK lights IN THE FLESH, or one of their generic cousins if they exist.

    Short of this, a source referral to the desirable components either by name or location would be very useful.

    ( EX: I like 'XYZ' brand reflector available from, or manufactured by 'XYZ' company, simply because . . . . )

    I build boats and racecars, so I'm less geared to sourcing and building custom light fixtures. For me it's not the act of building the fixture that gives me pause, but the inevitable time, trials, and errors associated with sourcing, choosing, and matching the various parts to make the whole perform as envisioned, without practical referrals from those that had been the route, learned what is very good, and who know where to get the components to duplicate their experience. Otherwise, I need to get something plug-n-play. And if something plug-n-play under consideration is substandard or flawed in ways that can be addressed, what is a competing product that is better? Who manufactures it? Where is a good place to buy it?

    PS - Don't worry about me falling prey to any lamp vendor's sales hype . . if I took it all as gospel, I wouldnt be here pestering you guys for answers. In the boat and racecar world I've heard it all and while some issues are subjective, nearly all are slaves to the bottom line and the timeclock. So my selective and intuitive listening has become a performance art.

    Thanks again,
    Phil

  • 16 years ago
    last modified: 9 years ago

    Instead of trying to explain via physics why one lighting system may or may not be better, or more efficient, or have more penetration...has anyone actually bothered to grow the same plant under different set-ups for an extended period, and compare the results? Wouldn't that be the ultimate answer to the debate?

    Has anyone grown marijuana under HID and CFL, and have some tangible results? Or flowered orchids? Or grown tomatoes? Or kept a coleus? Or managed to get a Cheiridopsis to flower during an English winter (shrubs, that one's for you :-)?

    a confused, x

  • 16 years ago
    last modified: 9 years ago

    I've grown marijuana under HID, exactly 2 x 400 w per 3'x5'
    growing closet, Gavita HPS. The plants grow 3-4' tall, they're bushy as hell, very heavy with bud, and when you admire your crop, it's just like you're out in a wide open field. You just cannot accomplish this with fluorescent. I use fluoros for seedlings, and if you only have fluoros you need to do SOG or SCROG methods for growing short plants.
    I don't grow anymore, because there's too much hassle when LEO raids your place, he confiscates your gro, and vandalizes ur place while he's at it, but yes, I'm somewhat of an expert in this subject. So for grass ur better off buying it, because it really wrecks ur life when u get thrown in a dog cage. Right now I just grow rose cuttings under a fluorescent bank and they do fine, but I don't plan on smoking them. Paul Mozarowski.

  • 16 years ago
    last modified: 9 years ago

    I've brought an Odontophorus into bud under lights. Then the bud aborted when I put it outside :( Cheiridopsis are far too easy, I'm working on Gibbaeums!

    Side by side trials are much more difficult than it might appear. The various lighting types cannot be fitted with the same reflectors, cannot be persuaded to light the same area, or provide the same collimation of the light, and it is hard to maintain the same temperature levels at the plant. It is hard enough even to provide an equivalent level of light, whether measured by input power or output light. Hence you get different results with different plants at different times.

    Results from full-fledged published side-by-side trials, not done by me, show some variation but also consistent trends. Plant yield, measured by the weight of the plants and any crop from the plants from a given input power, is consistently highest with HPS lights, followed by metal halides and fluorescent lighting. The two papers I could find that included LPS lights obtained the highest yields from the LPS but commented on the extreme etiolation and poor colour of the plants. Studies have shown that comparable yields to HPS can be obtained using mainly LEDs at around 670nm, using LEDs of an efficiency not widely or cheaply available yet but its only a matter of time. There is certainly room for more study, much of the research was done decades ago using lighting technology far inferior to stuff you can pick up today at Home Depot.

    It is simpler to compare different spectrums from the same technology. Again, it is hard to know if you are comparing a results from a different spectrum or from a different light output level, but if it is coming from the same input power, in the same reflector, then at least you can choose which bulb is best. My own testing is that triphosphor warm white colours do not provide as much growth as cool white and daylight colours, but there is no noticeable difference between cool white (4100K) and daylight (6500K). Wide spectrum, high CRI, fluorescents were a major non-no, I presume because of their overall lower light output.

  • 16 years ago
    last modified: 9 years ago

    My mesembs have been under a 1000W metal halide for about 3 weeks now since being in the greenhouse, it's enough to push Gibbaeum buds along, and the rest of the winter bloomers too. It's my 2nd winter using the HID. I used to keep them directly underneath a bank of fluorescent bulbs. The fluorescents were adequate for maintaining the plants in vegetative health, but not for flowering.

    FWIW, I have some tropical hibiscus that are under fluorescent lights right now just to sustain them through the winter, and some are forming new flower buds even with temps not higher than 55F.

  • 16 years ago
    last modified: 9 years ago

    Ah the memories . . . funny stuff. At the dawn of the 80's my college roommates and I had the idea that growing our stash at home would save us all a bundle, be great, etc. etc. Some months later after using a 1000W Metal Halide grow light, we harvested the most incredible looking, smelling and tasting pot plants we had ever seen. The only problem was, smoking it had almost no effect. By the time we added up the cost of materials and electricity alone, we would have been better off buying the stuff even if what we had grown had turned out 'chronic'! Live and learn :))) That was the first and only time I have ever used a grow light. Now I'm sure bulbs or plant genetics have improved since then, but because I won't be smoking my pineapple plants - or for that matter home-growing to save money, maybe I'll have better luck. On the other hand, your experience using the HPS for the purpose mentioned may actually be applicable to what I'm doing. A number of the plants types I and an Aussie friend of mine are interested in experimenting with bear fruit, and grow best in latitudes having pretty intense sunlight, not just long days. I would be just as disappointed as I was so many years ago if I ended up with exotic fruit that looked and smelled exotic - but tasted like exotic gym socks!
    All things claimed equal, my gut instinct would be to go with some type of HID fixture, but having only 3' of height in the area for growing, a lamp like that would probably fry anything trying to grow under it. Though I could then make toast in the downstairs bathroom. Tomorrow is promised to the garden. I'll look around and think about where else here I might be able to set up. If I can come up with a taller space, that would open the option of using an HID lamp. And then too, being able to elevate the fixture more should reduce shadows.
    One of the big pluses of being able to utilize an HID is the fact that there are so many modern units available secondhand for a fraction of the cost of new HID or fluorescent. For example there was a late model 1000W Sun Supply fixture and ballast without a bulb at the local swap meet a few weeks ago. The thing was reportedly used, but looked brand new and asking price was $75 for a $300-some-odd dollar lamp setup. They might have even taken less. And there also seems to be a big selection HID bulbs available from a large pool of suppliers.
    Hey thanks again Paul, you have made some good points, and I appreciate you sharing your experience. Reminding me of my college days brought a huge smile to my face, and talking about it got a roll of the eyes from my girlfriend . . . which is good for an even bigger smile with a grin tacked on for good measure :))))

    I'll let you guys know in a few days what I figure out.

    Best to all,
    Phil

  • 16 years ago
    last modified: 9 years ago

    You know, I started my last post this morning and got called away all day. I should have refreshed this evening before finishing so I could have seen the two additional responses and comment on those. But here goes -

    Shrubs - very, very interesting stuff, particularly your actual experiences with the flowering genus you mentioned. Also it is totally understandable the point you make about the difficulty of fairly comparing the competing technologies. And wouldn't it be nice if a real LED solution was available . . and cost effective. LED's sure have offered improvements in transportation lighting. My boat's nav lights, courtesy lights, and locker lighting are all LED. They work beautifully and consume far less energy. This is a big deal when passagmaking.

    xerophyte_nyc - Maybe you should make some hibiscus tea to see if those flowers look and smell nice, but taste awful compared to their outdoor cousins :)))) Thanks for the sharing your experiences - very . . (wince) . . illuminating!

    Phil

  • 16 years ago
    last modified: 9 years ago

    UV light is probably what's missing in most artificial lighting set-ups. One has to think that UV radiation can have a dramatic influence on flowers, fruit, and...bud

  • 16 years ago
    last modified: 9 years ago

    Its interesting to note that UV is also limited inside a greenhouse. Probably most of you don't grow much in a greenhouse, a glass or plastic structure outdoors in the sun, but I do. The effects of limited UV, especially at the shorter wavelengths, are much debated but there definitely are effects.

  • 16 years ago
    last modified: 9 years ago

    Humans do not see UV light, but many insects find flowers using UV light.

    dcarch

  • 16 years ago
    last modified: 9 years ago

    72 rooted cuttings, just fits perfect in my 4x6" fluorescent bank garden, all potted in 6x6x6.5" square plastic pots, and
    I've put the pots in under the bed plastic storage trays for watering purposes. I've just finished watering with 40 litres of water with dilute miracle-gro soluble fertilizer., 10 litres per storage tray. The lighting right now is normal driven it's supplying about
    2000 - 2500 foot candles at a distance of 1 foot from the fluorescent bank. I'm going to leave the lights on continuous 24/7, and when the bushes start getting bigger, turn on the overdrive. :) Paul Mozarowski.

  • 16 years ago
    last modified: 9 years ago

    I wonder if there is a convenient way to measure and quantify the UV light needed in an artificial growing environment, to duplicate what is naturally available outdoors. I recently inherited a second hand water sterilizer that had come from a mega-yacht refit. I'll use it for a water feature project I'm planning for summer. It's an all stainless steel affair having a 2' UV-C fluorescent bulb within it's cylindrical sterilization chamber. It's inlet and outlets are 3/4" and supposedly it can sterilize effectively at full flow. This is an NSF and EPA approved device that evidently is able to kill just about every kind of organism present in the water flowing through it by penetrating the organism's cell walls and damaging their DNA. UV-C? And I thought a 'black light' was a black light, and without Jimmy Hendricks posters to illuminate, had little other practical use. At the time I bought it, I researched the availability of bulbs and found that UV-A, -B, and -C were all available, and a few combinations of these as well - and not just in a florescent format.

    Next to think about, is the use of Solatubes through the ceiling to supplement artificial growing with natural light. I wonder what is lost from the naturally available spectrum when these are used? These devices use no glass, and seem to collect and intensify visible sunlight. I'm wondering about loss though because there seems to be little heat transmitted through them. . reduction of IR? I have never run across a discussion of these devices in the context of indoor gardening. Solatubes aren't cheap, but their cost can often be justified as an element of home improvement, not just an indoor growing tool.

    Here are a few interesting general references to UV light and bulbs I had found at the time -

    http://www.americanairandwater.com/uv-facts/uv-light.htm

    http://members.misty.com/don/uvbulb.html

    Reading the above got me to wondering if a modified surplus tanning booth might make an awesome grow 'chamber' with the right combination of bulbs. There are probably more tanning booths here in 'sunny' Southern California than anywhere that actually might need them, so there's bound to be surplus equipment available.

    Dcarch - interesting about the insects. If we could only find a way to use invisible UV emissions to detect a lamp marketer's BS . . I'm just sayin'.

    Phil

  • 16 years ago
    last modified: 9 years ago

    Just a quick followup: I noticed some of my cuttings were
    yellow due I think to the intensity of the overdrive. I've cut back the lighting to regular drive, 32 watts per T8 tube, and I've noticed in two days, the plants with yellow leaves are now developing green leaves, and the yellow leaves are greening up a bit. I think this means that an overdriven T8 garden can actually deliver too much intensity.
    Paul Mozarowski.

  • 16 years ago
    last modified: 9 years ago

    Hey Paul,
    Didn't you mention you were giving your plants light 24/7?
    I thought that nearly all plants use (and need) the normally dark period between each day to convert their sugars. It may also be worth considering that with a dark period, overdriving (greater intensity) may be just fine. I just can't get my head around fluorescents being more intense than the sun, overdriven or not. But thats just intuition, not science. Also, I could see if intensity was suddenly 'switched' higher that certain plants would suffer the same 'burn' effects as plants pulled out of a shady place in the garden to out in the open sun without time to acclimate. So maybe adding a dark period each day and acclimating the plants to the higher light intensity over a reasonable period of time would solve the problem. Just a few thoughts . . . It would be interesting to know the results.
    Phil

  • 16 years ago
    last modified: 9 years ago

    Each morning when I get up, and evening when I come home, I notice my plants have all grown some. Buds get bigger, start to leaf out, flower buds appear, get bigger, etc. I read somewhere that someone claimed that roots need darkness to grow, but my roses didn't read about that, so when I went to transplant them 5 days ago, they all had immense root systems, and since then the stems are getting bigger and the entire stem is showing swelling of all of the buds all the way down to the basal bud, and leafing out of the buds. The plants are obviously converting sugars in broad daylight.
    Since transplanting they have gained more leaves, more buds are opening up, and on some plants that had yellowed leaves, the yellow leaves are turning brown and shrivelling up, while new large green/red leaves are taking their place.
    They are just really obviously thriving on 24/7, constant 71 degrees F. Using 10x phillips 3000K high lumen 830's, alternating with 10 x Ushio 5000K 850's. normally driven. (I know, I should have just bought all Phillips 4100K high lumen). also, the fluoros have a maximum life when left on continuously, they'll proly go 3-4 yrs before I need to relamp. Right now I'm reading about Neem oil, need to really blast those spider mites, I get a little colony showing up in a cluster of plants every day. I'm going to strip all lower leaves tomorrow and spray the underneath of all leaves, spray down all buds and stems with the oil suspension, repeat every 4-5 days for a month. I hope to be able to take cuttings from cuttings, and I would like to see a healthy generation.
    p.s. my intensity at the plant level is only 1/4 of midday sun. It is possible that on 24/7 the plant cannot tolerate as high an intensity as it might otherwise if it had a normal diurnal variation. This might account for why some plants had yellow leaves when exposed to overdrive, and are turning green now that the lighting is more "sensible" i.e. conventional intensities. Paul.
    Paul

  • 16 years ago
    last modified: 9 years ago

    Try anti-stress 2000 to get rid of mites. It is an anti-desiccant that incidentally also eradicates spider mites after 1 or 2 applications. It is not a pesticide, so is harmless. I have used it and am amazed at the results.

    I think either the mites are unable to penetrate the polymer coating with their "mouths", or somehow the polymer coats the mites themselves and suffocates them.

    Also, I think photoperiodicity is species specific. Some plants have no problems growing with 24-7 light, others will weaken.

    x

  • 16 years ago
    last modified: 9 years ago

    Another non-pesticide mite treatment is to spray alcohol on them. You can use vodka, but rubbing alcohol is perhaps a better idea. It kills the mites by contact so you have to spray all the nooks and crannies, then it evaporates. Although it may seem counter-intuitive, you shouldn't dilute the alcohol because it works by dessicating the mites. Make it dilute and it won't dessicate anything, just get them drunk! Don't use in strong sun or you will certainly scorch your plants. And watch out for those sensitive succulents like Crassulas. What is it they say, "test on an inconspicuous area first" :)

    Photoperiodicity is different from whether a plant will grow well under 24/7 light. Photoperiodicity is a response to the length of the dark period which controls seasonal events like flowering and dormancy. Certain plants will simply not grow well under continuous light, typically succulents which only open their stomata when it is dark, but also some other plants.

  • 16 years ago
    last modified: 9 years ago

    I'll try adding 10ml. Neem Oil per litre of 70% rubbing alcohol, with 20ml of insecticidal soap thrown in :)
    I'll call it the "radical cure" - the patient will either be cured or killed. Here goes ...
    Paul Mozarowski

  • 16 years ago
    last modified: 9 years ago

    Hi all ... new member here

    Well if it wasn't for shrubs I would not have even bothered.

    Shrubs ... you know what you are talking about ... or at least you know a lot more then I do about growing. However.

    I build LED Growing Systems for a living and I have yet to find Red Led's that are of the wavelengths you are talking about. Red led's are typically 630nm ... not 680 or 690 ... if they were they would outstrip all other growing methods tomorow. Unfortunatelly commercially available blues are also slightly off the required wavelength. They are 470nm and plants want 430nm.

    As to the cost of Led growing systems I will pull my own chain here as I am about to release on eBay an all white panel ... watch for it ... made in Canada as well.

    Here are as I see them the challenges to using Leds.

    1. Density ... how many leds can you AFFORD to fit on a panel.

    2. Size and type of Led .. is a 5mm twice as bright as a 10mm and if so... does it matter? Is brightnest what we really want?

    3. You need to analyze the absorption sprectrum VS the emmision spectrum of the plant in question. Somebody in this thread said that plants like UV light because the bugs see it. What they are describing is the emmision spectrum of that plant and the ability of the bug to see it.

    4. ONLY leds can produce basically monochomatic light and can therefore be programmed...what I mean by this is that I can build a timer circuit that would turn on 730nm and 830nm Infrared light for a few minutes just before the end of the daily photoperiod. Why on earth would you want to do that... as you are no doubt scratching your head about now.

    For the answer to this point please research the Emerson Effect and co related studies.

    As for the comment that you made that many studies have been done using 690nm light...where are they...I have been reaserching this subject for a long time and I have not seen a single one...that is probably because they don't make them.

    Again the main and posibly only challenges about led lighting are capital costs and what I call the blue red shift

    LED available
    red 630nm
    blue 470 nm

    Plant wants
    red 660 at daytime
    680nm , 730, and a tiny , very tiny 830nm shot in the dark so to speak
    blue 430

    As to Efficiency ... another word misused in this thread.

    First of all a Watt is a Watt whether it is produced by 220v or 110v ac or DC voltage. Therefore efficiency is a matter of watts in vs watts out and it is that simple for most calculations.

    If you want to improve efficiency ... look to your power supply not the light as you have no control over that.

    Having said that this makes leds very attractive from a power consumption point of view as they ... or at least mine ... are designed using Level IV Efficiency rated supplys.

    Look at the rating on MH or HPS supply or use a meter to figure it out .. no shocks please.

    So the claim that leds will reduce your power bill by 90% is true. I calculate 96% actually. But now you have a new problem ... beleive it or not the room is too cold and dry. I use the excess heat from my computer room to heat the grow room. Ratio is one AMD chip to ten plants or one Intel to three plants (Intel runs cooler).

    Also if you increase the density to pot growing needs you need to double up. But after the first electrical bill your already that much closer to electrical independance. Which is after all the holy grail of growing.

    All in all we need people out there trying leds to see what the combination of colors and photoperiods can do for us...there are just far, far too many for any one person to figure this out.

    As a matter of fact I would love any assistance I can get on the absorption spetrum of plants, the photoperiods required, etc... So

    WATCH FOR MY WEB SITE ON LED GROWING SYSTEMS IN THE NEXT WEEK...I will return and supply the link to this club in a couple of days...don't expect miracles as it will be brand new and I have no help...yet!

    shrubs I would very much like your help.

  • 16 years ago
    last modified: 9 years ago

    What do you need my help for? Sounds like you have the marketing patter down straight ;)

    I'm not sure what your issue with sourcing LEDs at the correct wavelength. 660nm is very readily available as a component LED. Manufactured products at this wavelength are rare because it looks so dim. 670nm are also available, this is right at the chlorophyll absorption peak. Beyond that, you are like to find 680nm and 690 nm lumped in with the IR LEDs since they are almost invisible to human eyes.

    Anybody selling LED plant lights operating at 630nm is a conman and anyone buying them is a fool. If you want light at 630nm then buy a fluorescent. You can actually get fluorescents that use only the red triphosphor if you really want to load it on at that wavelength. Use an LED light if you want your light right at that 660/670nm wavelength.

  • 16 years ago
    last modified: 9 years ago

    aztec2012,

    First, I am glad that different people try different things, thats what progress is all about. So dont take any of my comments here as being negative.

    1. Manufacturers will be unlikely to gear-up to produce LEDs with spectrums specifically for plant growth because it is more profitable for them to use their capacities to produce LEDs for other applications.

    2. It is my own believe that plants grow better with a whole range of light spectrums. LEDs is monochromatic. Vitamins are important to human health, but I dont think you will do well just eating vitamin pills.

    3. "Density ... how many leds can you AFFORD to fit on a panel",
    Not only that, heat kills LEDs quickly. When you pack LEDs, heat evacuation becomes a major issue.

    4. "Size and type of Led .. is a 5mm twice as bright as a 10mm and if so... does it matter? Is brightnest what we really want?"
    Absolutely!

    5. LEDs have built-in lenses, that severely limits your options in light distribution design. Its very difficult to use reflectors for LED arrays.

    6. "ONLY leds can produce basically monochromatic light and can therefore be programmed...what I mean by this is that I can build a timer circuit that would turn on 730nm and 830nm Infrared light for a few minutes ".
    You can turn any lights on/off, not just LEDs.

    7. "First of all a Watt is a Watt whether it is produced by 220v or 110v ac or DC voltage. Therefore efficiency is a matter of watts in vs watts out and it is that simple for most calculations. "
    Not sure whats your point. In lighting, efficiency is watts vs foot-candles.

    8. "Having said that this makes leds very attractive from a power consumption point of view as they ... or at least mine ... are designed using Level IV Efficiency rated supplys."
    Again, I am not sure whats your point. You can have a 100% efficient power supply and still useless if your light source is only 50% efficient.

    9. "believe it or not the room is too cold and dry. I use the excess heat from my computer room to heat the grow room."
    I dont quite understand. A computer uses less than a 100 watts of power. 100w x 3.4 = 3,400 btu/hr, even you add other devices there is still not enough to heat any room (in the summer may be).

    10. "Also if you increase the density to pot growing needs you need to double up."
    If you are talking about pot as in containers, again, you need as much foot-candles of all spectrums as possible. If you are talking about pot as in cannabis, yes, they will try anything, spin lights, moving lights, LED lights, they have plenty of money to burn.

    dcarch

  • 16 years ago
    last modified: 9 years ago

    Ok, let's see . . . a thousand 15-degree super-bright LED's of the type I purchased last year for a navigation light experiment at $1.25 apiece should make a good fixture . . .
    plus wire, fixture materials, labor, packaging, and shipping.

    Maaaan, that is one EXPENSIVE grow light.

    But of course if it could efficiently grow Thai house-girls I might write the check :)))

    Phil

  • 16 years ago
    last modified: 9 years ago

    Well I expected some good responses, some criticism, but wow!

    To Shrubs

    Yes they do make them and they are not usually from China either. But I misspoke before...it wasn't the leds...it was the reports I wanted...where are they...please provide links. I want to read all I can and find the proper wavelength of leds.

    I disagree with your second point however due to the radiation pattern of red leds...they do have components in the proper wavelengths but like MH and HPS you have to turn up the other wavelengths in order to get the ones you really want. But buy a fluorescent...that is a bit harsh.

    How about a comprimise..could not one supplement the other in order to acheive the conditions of nature.

    I would like your help for the obvious knowledge you have with growing. I guess questions in this forum would be enough but I was hoping to get you to try advanced techniques like Infrared. I can make all Led panels...using any led. I thought you might start a site like greenpinelane. Interested?

    I considered well your point about raising lights vs lowering them and you are absolutely right and the sun proves it. By the time the rays get to the earth their power is even thru out the plant worlds short height of 100 meters or so as in the jungle and that also explains the shadow problem that other fellow thought he had but didn't.

    To dcarch

    you are in left field for most of your 1 thru 10 points.I won't hit them one by one that would take too long.

    First of all I MANUFACTURE LED PANELS I am not buying them. I have only made a few dozen so far as I am a startup and as far as them being hot...what planet are you on...they do not get hot AT ALL the resistors do! Not the leds themselves. If you are refering to High Power Leds then diferent story.. I am refering to standard 20ma Leds which is all you need. you don't need the new 1W or 10W leds for plants you can even get away with 5mm spaced at a half inch.. my own panel has 300 leds spaced very close and there is no heat whatsoever...none at all. The room is hotter.

    You have answered some of my questions tho. Bright is allways better you say. Well how bright should I make the Infrared considering I can't see it! As far as a light switch goes well you can stand their with a watch and turn on the IR at the end of the night and you can stand there and turn the knob that simulates the falling sun but I would rather put all that in a circuit to do the job for me.

    As for efficiency. As allways people comming from the visible light world keep thinking of things like lumens per watt and such things. Therefore your argument about foot-candles goes out the door and we talk instead about micro einsteins. Either way your argument is irrelevant because it has no place in the monochromatic world, which after all is a plants world. So you are absolutely wrong about a plant requiring the full spectrum of light. If that were true then plants would all be black..or would they all be white. Either way they would not be green. This is very simple. Furthermore...why is NASA using leds on the space station and on the mission to Mars if they don't work?

    The next time you write a novel do some research, you are wrong on 90% of your points. The only one you had right was brighter is better.

    I do in fact use the excess heat from my computer ROOM run thru a bathroom fan to heat and fan my plants and it works! I'm looking at it right now. If I could upload a picture I would. But I really said it a a joke ...you know...I didn't think anyone would take me seriously on that point. Call it a test.

    Leds have built in lenses.. my god I hope so!!!! However light distribution is not what I want...I want the ability to concentrate the light in an area not throw it all over the room so again leds win!

    Efficiency is not watts vs foot candles in an led world. It is the efficiecy of the power supply that matters. I don't manufacture the led's, I just use them, so I can't waste my time worrying about whether they are as efficient as other lights. hell they are all inefficient for that matter. What I care about is the power bill for the plant I get. that's all. Who cares about the rest of the power equation. You can't change it!

    Light source only 50%...???? what the...

    You are so wrong on that last point it is not even funny...do your reasearch on the four types of chlorophyll ( a thru d ... yes there are more then two types) and their ABSORPTION SPECTRUM with respect to the plant you are growing and then see if you have a new view point

  • 16 years ago
    last modified: 9 years ago

    aztec2012
    "First of all I MANUFACTURE LED PANELS I am not buying them. I have only made a few dozen so far as I am a startup and as far as them being hot...what planet are you on..."
    With some of the people I come across here, I do wonder what planet I am on lots of times. You certainly have an interesting manner of communicating. So let me learn a few more lessons from you:

    I have been assembling quite a few LED devices for various applications using different types of LEDs. It is my experience that 5mm LEDs do generate significant amount of heat, if driven to their rated power. With higher power LEDs (Cree, Luxeon, K2, Rebel, etc.) They will not last more than a few seconds if not properly heat sinked. Obviously, by definition, resistors turn power into heat, thats where system inefficiency becomes unavoidable. I was hoping that you would be using electronic regulated driver power supply to get better efficiency as well as better reliability. If all you are doing is running LEDs in series with resistors after DC rectifiers, then LEDs intolerance to voltage spikes becomes an issue.

    "Well how bright should I make the Infrared considering I can't see it!"
    It is of course very silly for me to tell you this, as it sounds like you know so much already. But here it is, I use my digital cameras viewer to view infrared from my IR LEDs.

    "As far as a light switch goes well you can stand their with a watch and turn on the IR at the end of the night and you can stand there and turn the knob that simulates the falling sun but I would rather put all that in a circuit to do the job for me. "
    I humbly apologize. I didnt know you have such mastery of digital circuit design. I recently have built, in such clumsy way and with such difficulty, a working solid-state light timer which has adjustable dimming on/dimming off (sunrise/sunset) controls. Unfortunately it is at this point for incandescent lights only, as I am still having difficult figuring out how to dim LEDs gradually. Perhaps you can help.

    "As for efficiency. As allways people comming from the visible light world keep thinking of things like lumens per watt and such things. Therefore your argument about foot-candles goes out the door "
    I am too old to understand new concepts. If I pay for watts, I want to know how many foot-candles or lumens I am getting back.

    "So you are absolutely wrong about a plant requiring the full spectrum of light. If that were true then plants would all be black.."
    I know a few black friends, may be they can explain to me better.

    "The next time you write a novel do some research, you are wrong on 90% of your points. The only one you had right was brighter is better. "
    Thank you for your complement that I am 10% right.

    "Leds have built in lenses.. my god I hope so!!!! However light distribution is not what I want...I want the ability to concentrate the light in an area not throw it all over the room so again leds win! "
    So with say a 20 degree typical beam spread for LED lens, I should be able to keep my one tomato plant happy, NO?

    "so I can't waste my time worrying about whether they are as efficient as other lights. -------- Who cares about the rest of the power equation-----"
    Yeah! right on! Dont worry, be happy, life is too short.

    "You are so wrong on that last point it is not even funny..."
    I have been told many a times I dont have a good sense of humor.

    dcarch

  • 16 years ago
    last modified: 9 years ago

    aztec, I started to write a detailed reply to your points but gave up. Your responses to dcarch in particular show a serious misunderstanding of the whole subject. For example, you cannot seriously think that the power supply is the important factor in the chain. Even the obsolete technology magnetic ballast power supply that I tell everyone they shouldn't be using any more is over 80% efficient (and electronic ballasts are about 95% efficient), while the actual LED only converts about 20% of the input power to light (compared to 30% for conventional plant lighting technology), it is clear where the weak link is.

    And your responses to me in particular show that you are refusing to accept the basic laws of the universe. I repeat again and perhaps you will read it this time: if an LED light outputs the same wavelengths that a fluorescent light outputs (eg. 630nm and 420nm) then you should throw it away and use the fluorescent because it produces more light (in 2007/8 with commercially available LEDs) for a given input power. No attempt to bootstrap up a perpetual motion machine with IR flashes are going to change that. Until available LEDs roughly double their output efficiency, they can only be effective as plant lights by doing something that other technology cannot. At present this appears to be producing light predominantly near 670nm which no other light can do.

  • 16 years ago
    last modified: 9 years ago

    I just noticed a point about dimming LEDs. So far as I know the generally accepted method for dimming an LED is to "flicker" it, simply switching it on and off quickly in the proportion required to get the correct output. LEDs will dim when you lower the voltage across them but the relationship is very sharp, the dimming range is not huge, and both bulb life and efficiency can be harmed.

  • 16 years ago
    last modified: 9 years ago

    shrubs,
    That was the challenge. Once you are near the LED's forward voltage threshold, there is not much range for dimming.

    A sunrise/sunset dimmer will need very smooth full range (100% to 0%)dimming for about 45 minutes. I did it using zener controlled charging circuit to charge a capcitor and disipate the current over an adjustable resistor (temperature compensated). This circuit is then used to control the gate of the power portion of the circuit to a 500w halogen light.

    BTW, this type of dimmer is useful for people who are into birds, and other pets, not for plants.

    dcarch

  • 16 years ago
    last modified: 9 years ago

    I like to have staged lighting so that I can get the intensity needed for good colour and shape (I grow succulents and cacti) but without stressing the plants by maintaining that midday intensity for 12 or more hours straight. Just something simple like 1,500fc for a few hours, then 3,000fc for a few hours, back to 1,500fc, then off, or whatever your plants need. In practice I don't usually bother since I mostly use the lights for overwintering and seedlings, and for them a single max-on-off sequence works fine.

  • 16 years ago
    last modified: 9 years ago

    Well guys this is my last post. I have found another forum where they know what they are talking about! They are doing several experiments with leds and the IR lighting effects.

    Here are my comebacks...which is all you guys seem to want to do..argue that is...how about trying to cooperate in order to acheive a goal. Or do you all just want to be right?

    dcarch

    You have no clue dude...use constant current or regulated 5volt supllies..use Toshiba 16 channel LED driver..one resitor and a 555 timer and voila a circuit that can dim from 40% to 110% of relative illumanance, (no flicker?????)
    be contrlloed in any way I see fit and DOES NOT GET HOT AT ALL >>> NO RESISTORS.

    There are many ways to connect Leds not just the standard. Again do your research which I know you have not done because you just rattled off an answer to me without taking the time to check any of my research...but your so smart.

    Well dcarch I won't bother responding to a guy who doesn't take the time to read!

    shrubs...go buy a flourescent bulb ... you also have no clue as your answers show..and I thought you were smart.

    And if you think that a flourescent can compare to leds then you need to buy a spetral analyzer dude cause you are way wrong.

    Anyway guys go ahead and argue with me since that's all that's going on here anyway and I will come back in a few days and show you where the real work is getting done...not this farce of a dicussion group!

    I will even tell you where my site is so you can and buy real led grow lights!!

  • 16 years ago
    last modified: 9 years ago

    aztec,

    "You have no clue dude...use constant current or regulated 5volt supllies..use Toshiba 16 channel LED driver..one resitor and a 555 timer and voila a circuit that can dim from 40% to 110% -------------,"

    Thanks again for the education, as I said, I am too old and cannot remember how to use this IC timer 555, which was made 36 years ago and long discontinued. But now that you have reminded me, I will have to go to some antique shop to find one. I am very interested to be able to dim LEDs from 40% to 110% even all I need is to dim from 100% down to 0%.

    "There are many ways to connect Leds not just the standard.----------"
    That I am sure you have found a great way to connect them. Because 300 LEDs x 2 connections = 600 soldering connections, the fume from the soldering flux can reconnect quite a few of your brain cells in the wrong way.

    "I will even tell you where my site is so you can and buy real led grow lights!! "
    Yes, that would be nice. Do me a big favor; put me down for 10 of those panels before other pot growers empty out you stock.

    BTW, I like the name you gave me,

    dcarch, aka no-clue-duke

  • 16 years ago
    last modified: 9 years ago

    No probs, Aztec, it was nice meeting someone who only has an agenda and isn't actually interested in facts. NOT!

    Anyway, I'm off too. I'm fed up arguing with idiots who are only interested in promoting their own products and have no interest in giving sensible advice to people or on actually learning what on earth they are doing. I really really hate people who decide what they are going to believe first, then hunt around for facts to support it and ignore anything that doesn't match their pre-conceived notions.

    Sorry to anyone who wanted some impartial advice, I'll be hanging out somewhere that isn't populated by spammers. Here's a couple of places you might find me, not specifically lighting related, just for people who like to grow plants if you can believe that ;)

    The Garden Forums
    Cacti Guide

  • 16 years ago
    last modified: 9 years ago

    dcarch

    Come on dude...what is your problem. 555 timers are not obsolete..they work. I too have been using them for about 30 years so I don't see your point about an antique shop..but I do see that you had nothing to say about the Toshiba led drivers which you didn't know about.

    And yes it is a lot of work if you solder by hand ... but they make things like high speed pickers and wave solder machines for these purposes so again you have no point!

    Personally I make grow lights. I don't care if you grow pot or petunias. I make electronic products and if you want to buy I won't discriminate against you because of your obvious hang up on pot growers. I'm Canadian and we really don't care about YOUR pot laws! Or your prejudices!

    As for dimming led from 40% to 110% RTFM, go to Toshiba you idiot and read for once instead of opening your yap!

    Shrubs I could care less about promoting MY PRODUCT I AM INTERESTED IN MAKING THE BEST LED PANEL I CAN FOR YOU GROWERS!

    I don't grow anything, I need input from growers to know what blue/red/infrared ratio they want. As a matter of fact I intend on doing something for growers that no other led manufacturer would do. I have a downloadable program that allows you to design your own led panel and send me the plans and I will put it in my casing system.

    I wanted your help in that, but you like the rest of these fools have an attitude problem...I am only trying to build the best panel posible and save money for my friends...I DON'T NEED THE MONEY I'M DOING THIS BECAUSE I WANT TO!

    My friends asked me to do this...I have a bunch of pot head programmer friends and they wanted cheap lights...so here I am ...I have spent $5000 so far just setting up a small shop and I'll end up spending about $25,000 when I'm done...but like I said ...money is not the issue for me.

    I want good lights to save people electrical bill money ... that's all. So I could care less if you or anyone else buys one. I already have the ones I was asked to build sold!

  • 16 years ago
    last modified: 9 years ago

    The overgrow forum used to have an LED grow thread. People can gro in a computer case using LED's. You need to make a prototype, have beta testers, and then market. Let me know if I can help. Paul Mozarowski.

  • 16 years ago
    last modified: 9 years ago

    "I'm Canadian and we really don't care about YOUR pot laws! Or your prejudices! "

    So how did you get from Australia to Canada?

    dcarch

  • 16 years ago
    last modified: 9 years ago
  • 16 years ago
    last modified: 9 years ago

    Aztec2012.. Can you email me the link to your web page on these LED lights Thank you... tprav@aol.com

  • 15 years ago
    last modified: 9 years ago

    I built an LED grow light out of pre wired 10 mm super bright blue LEDs I have about 50 Bulbs in a 2x4 area it is very bright. After reading some of the posts , I starting to think I need to add some red LED's and some UV LED's.

    My question is do plants require UV light or can they grow without they also have limited winter sunlight.

    Fluorescents are ok you could use the new T-5 fixtures which give off the same light as a 400 w mh, OR you could use HID lights, But I want to conserve on energy so I am using LEDs.

    LEDs are expensive , but you could build a grow light for next to nothing if you know what your doing. I bought 100 LEDs at $0.66 each thats $70 , Less expensive then a High output Fluorescent, or an HID, it took me about 2 hours to build. I am an electrician by trade so I know my way around lights.

  • 15 years ago
    last modified: 9 years ago

    Also the problem with HID's and Fluorescents and possibly LEDs is they loose there brightness over time.

    A HID looses about 20% of its light in the first year and then keeps loosing light over time. A HID produces a lot of heat which is also a waist of energy.

    A Fluorescent Light uses less energy and heat, but contains mercury. It also looses light after awhile.

    Both systems create particle dust from the heat they produce kinda like your computer or TV and that also reduces light which you can clean the fixtures up and gain more light about 25% more.

    Also both of these systems require much maintenance , changing bulbs, ballasts, lamp holders which could result in high overall costs over time.

    LEDs on the other hand are the new oddity. We use lots of LEDs in the buildings we work in and I am getting more and more familiar with them. They use hardly any energy and they are evolving every day.

    You may have to change a ballast over time with them but they outlast HID and fluorescent by light years, no pun intended,lol! bulbs can last up to 50,000 hours or more and they don't create unwanted heat.

    We should all consider using lower energy systems anyway, incandescents and HID's are being phased out soon and we should start conserving energy anyway!

  • 15 years ago
    last modified: 9 years ago

    This post is like 2 years old, but im setting up a constant flow system, thats long and skinny and that part is basically done, now i just have to choose a lighting system. It seems like nasa likes the leds and they dont mess around. They dont use alot of energy wich is a plus too. The thing is that the leds are pretty steep in price. So i was thinking about putting them on movers. Would that make LEDs the best choice, or can you not put LEDs on movers?

  • 15 years ago
    last modified: 9 years ago

    Don't know about putting bulbs on a moving system. Find the exchange about efficacy of various systems boring after a while.

    I have an old armoire that is about 40 inches wide, 28 inches deep and 64 inches tall. Inside is a 105 watt, 5000K CFL bulb, along with two hydro chambers. One is a 5-gallon bucket, another a 22-gallon Sterlite tub. The tub has two cucumbers in it, the bucket two Green Sausage tomatoes. The light runs about 14 hours per day.

    The cukes are flowering and setting fruit and the tomato is growing nicely, but isn't quite old enough to flower just yet.

    I also have a chamber I built to germinate tomato and pepper seeds in. It also uses the 105 watt CFL lamps, spaced 30 inches apart. When I measure the lux at 15" from the middle of the bulb, at 10 inches below it, I get 7,000 lux.

    The bulbs cost $25 each, much cheaper than LEDs. I love the latter, especially the higher-powered ones, but they are too expensive at this point if one wants to cover a large area.

    Just my 2¢ worth.

    Mike

  • 15 years ago
    last modified: 9 years ago

    "Shrubs" opined:
    "Blue wavelengths are in no way preferable for vegetative growth or any other kind of growth. There is a sort of cult about blue light, almost entirely created by pot growers who desire it to increase alkaloid production in their cannabis plants."

    Lermer here. Shrubs is wrong here. Blue does stimulate growth hormones, and also reduces stem elongation and enhances rooting. Blue does not increase potency of pot, although UV-B does. Pot has no alkaloids at all.

    Generally the original poster is correct, however he overlooks Ceramic Metal Halide. Ideally you want both full spectrum and high intensity. However there is a trade-off between these two factors. Generally the best trade-off is Ceramic Metal Halide. The Philips CMH is 4K, better suited to veg stage; the GE CMH is 3K (and higher output), better suited to bloom stage.

  • 15 years ago
    last modified: 9 years ago

    I have been growing under fluoro's for a while now for tomat's and peppers and the t-8 have worked very well for me , so I decided to try some 225 mixed LED's for some seedlings as I have read about some success with this 14 watt setup, unfortunately the results were less than spectacular, albeit the plants did grow, and did not stretch I still got 2x the growth from the Fluoro in half the time. I cannot comment to the scientific explanation, but It appears that 14 watt LED over 1sq foot is not enough power to really drive growth, I guess the next step would be to focus 2 pannels on a single area.

  • 15 years ago
    last modified: 9 years ago

    If cost is a concern I don't think you can beat fluorescent lights. Right now Southern California Edison is subsidizing the cost of a plain jane looking four foot fluorescent light fixtures so they sell for $1.99 each. They are only about three inches wide, with no reflector other than the white painted body of the fixture, so you can pack them in as close as you want. They will take either a T8 or T12 fluorescent tube. A T12 bulb would cost around $1.88, even less on sale. So for four dollars each you could buy as many fluorescent fixtures with bulbs as you needed. They come unwired, so you would have to add in the cost of some wire, switches, power cord, junction boxes, wire nuts, etc. But unless you get really fancy that shouldn't come to more than ten or twenty dollars, even less if you already have a bunch of that stuff laying around like I do. I plan to build a three shelf seed starting setup with three tubes above each shelf. I will use one of those multi-outlet power strips, and plug each shelf into a separate outlet so I can just unplug or plug in a set of lights depending upon how many shelves will be in use.

  • 15 years ago
    last modified: 9 years ago

    Lermer is correct. Even a quick google search will reveal hundreds of peer-reviewed papers on blue light's effect on plants. It's no myth at all. Here's a random example. They took Scots pine seedlings and put them in plexiglass containers, one designed to remove blue light and the other completely clear. I.e., the ones missing blue light got less total light to them; however, they grew *longer* than the ones in the fully transparent plexiglass. I could point to countless more examples of this phenomenon. Blue = stocky and leafy. Red = spindly, encourages fruiting.

    Right now Southern California Edison is subsidizing the cost of a plain jane looking four foot fluorescent light fixtures so they sell for $1.99 each.

    Purchase cost isn't the only consideration. Power is generally a bigger cost than upfront costs. Think about drawing 450W for a HID on an 18/6 day/night cycle year-round -- that's 3,000kWh, or $325 a year at average electricity rates. That's no chump change. :P

    so I decided to try some 225 mixed LED's for some seedlings as I have read about some success with this 14 watt setup, unfortunately the results were less than spectacular, albeit the plants did grow, and did not stretch I still got 2x the growth from the Fluoro in half the time. I cannot comment to the scientific explanation, but It appears that 14 watt LED over 1sq foot is not enough power to really drive growth,

    Well, obviously ;) LEDs are nice, but they're not magical. The sun on a clear day puts down about 93 watts per square foot (times the sine of the angle to the sun -- if it's straight overhead, times 1.0). Even if your LEDs were 100% efficient, which they're not (for blue, probably a quantum efficiency in the 40%s) that'd still be 15% of the energy of sun shining directly overhead. In practice, factoring into account inefficiencies and light straying from where you intended to illuminate, you're probably getting under 5% of the light of the sun. Now, you get to pick your ideal frequencies, {{gwi:1032215}} (the graph at the bottom is what you want to look at). But that isn't nearly enough of a boost to compensate for how little light you're putting out.

    If you want to drive growth, you don't need to double your light; you should at least 4x it. And be sure to minimize any stray light that you can :) Also, as the plants get bigger, penetration will become an issue. LEDs are effectively point light sources; there's nearly no penumbra. The more reflections you can get and the deeper the LEDs are into the canopy (and the more they move, if that's an option), the better your results will be. I'm about to try an experiment with dangling LED christmas lights through my planters to see how they like that.

  • 15 years ago
    last modified: 9 years ago

    I am wondering if any of the people who posted over the last 2 years in this discussion thread have changed their mind about using the latest LED lights for growing. And if they have, do you have any new information about it you could share.

    I am finding that the LED's radiate so little heat to the plants that the leaves are staying moist and attracting mold. This is becoming a big problem.

    What attracted me to LED's was the fact that my 1000 watt HID gave 520 watts to unwanted heat. Then in the 480 watts of actual light going to the plants, the plants only needed some blue and lots of red, they didn't need to have the yellow and green etc. But I was paying my bulb to provide it. By using some blue and lots of red LED's I am only using 180 watts of LED's to replace the 1,000 watts that went to my HID system.

    I have found that tomatoes have lots of short internodel length when supplemented with extra red, most everyone I ask says it is blue light that would do this. My banana's can be made to stay under 7 feet tall using 3 15 watt 470nm bulbs on for 12 hours per day. Sometimes it is difficult for me to provide enough light for my pineapples and I get pineapples with out a crown. I have 24 pineapples under 3 35 watt panels [red 660nm] and they are all thriving. They are bigger than pineapples imported from Mexico and sweeter than anything from Hawaii.

    LED lights are really working for me.

  • 15 years ago
    last modified: 9 years ago

    This is my first year with an LED setup, but I have not had mold problems, in a grow chamber loosely but fully enclosed on all sides. For what that's worth. My watermelon did have some of its first seed leaves become shriveled somehow, but (as my next update will note), it's putting out a new set (actually working on the second new set) of true leaves and they're not having that problem.

  • 10 years ago
    last modified: 9 years ago

    I prefer HID lights because they are closer to natural light than other light bulbs allowing your plants to grow better more naturally. If you are interested you should check out www.lighting55.com to buy light bulbs for any of your indoor gardening projects and they are very affordable.

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