Are LEDs Misunderstood?

[knna]

And they're little emitters anyway cant do anything except SOG and similar stuff. I live in California and there is a per medical user plant limit. To be legit without being caretaker for a ton of people, you have to grow big. I've heard people getting good results with between 2 and 3 months veg using buckets. Little LEDs probably aren't going to do much in that situation.

Although I agree with most of your post, this paragraph shows a very typical misunderstanding of LED lighting, that I would like to correct.

LEDs allows you to grow very big plants, as only HID vertical lighting allowed before. With LEDs, you dont depends on the light penetration ability of the light, you can surround one or many plants with LEDs. As LEDs run cool, they can be close toplants without any problem,thus allowing to run big plants without the need of use excessive irradiances on top, that is a very inefficient way of lighting plant, but the only possible way before LEDs to grow big plants.

LEDs we are using now (1-2.5W of power each, wide angle) are having decent penetration, about 40-50cm (to produce compact buds), that can be improved if you use narrower beam angles. When we grow taller plants, its just a matter of putting one array each 30-40cm of height of the plant. As far as the plant is not wider than 80cm, you can grow it as tall as you want. We often try to give each cubic ft its own lighting module, consisting on little LEDs each. Some people is working on systems where LEDs go turning on as the plant grows, using just the energy needed for each stage and size of the plant.

The reason behind you see little grows this way currently is due the price factor. LEDs are currently a cost effective solution for small grows, but as total wattage increases, HIDs are cheaper actually. As the price/perfomance is improving fast, its just a matter of time to see LEDs running grows with very big plants. LED industry expectation is a 10 fold increase on perfomance/price for 2015 (base 2009), so its not going to be a long time at all.

 

[unthing]

yeah and pics and yield reports from indiviuals with different skills isn't the same as science, but with the current legal climate it's more practical to give generic idea what these things can do . Perfectionism in this situation is luxury that many don't have.

But those who are able to run some comparative tests, +++ to you.

 

[snowtiko]

maybe they are misunderstood, maybe not..until the price comes down and they yield what my 1k hps does they make no sense to me..
cost vs. yield vs. savings = led is not good buy..for the time being..
i'm sure as they evolve, they might be the future..

exactly

 

[GrnMtnGrwr]

To answer the original question...


Are LEDs Misunderstood?

Yes.

 

[PetFlora]

asde I am having trouble interpreting your comments. Can you be more specific like how many watts of CMH per 1cft, or more specifically a link to the products you recommend? Thanks

unthing Although I used FF organic soil when I grew under a 400, the soil pH might have been off, I might not have had enough drainage, though I added extra perlite, and I MAY have mxed the bloom nutes too hot. Other than that, maybe I had a bad transformer- it sure made a lot of noise.

This LED/CFL grow is close in overall size to your plants: My plants are plenty sticky, but I don't yet have the frosties. Guessing that is strain dependent.


knna (and others) I am going to give you one extremely important example of how a small thing to you (like UVb) might have a huge impact on quality (overall health/efficiency), and probably quantity.

Vitamin D-3 has only recently come to the fore in health discussions. It is found in sunlight and is essential to health. If you live in the nothern climates you will not get anywhere near the amount you need without daily supplementation of 5-10,000 units: even people who live in the tropics can be deficient if they don't get a good 15 minutes of quality sun each day. Getting it (or supplementing) is the difference between staying healthy or breaking down- disorders, diseases.

The only questions to me are

1. How much area does one CMH-UVb cover?
2. How much UVb should we have per cft?

 

[unthing]

Somebody correct if these answers are wrong

1.You mean area coverage? Quess you could same charts as for hps. Might be in the growguide. If you mean how much uv-b it emits, there might be something in the long ass cmh-thread or you could pm simba etc.

2.Nobody knows (yet)

 

[Matanuskan Flo]

once quantum dot technology is widely used in lighting sources, particularly LEDs, they will become much more efficient & viable than even now. any light sources is capable of being layered with the quantum dots & produce only a very specific nM, which could be tailored specifically for cannabis or whatever need be. ranges of nM will be a thing of the past, they QDs will emit exact 650nM or whatever is best for your strain. the technology is just now taking off in expensive LED TVs. its being used in nanotech for computer chips & semiconductors. also, its application in solar panel arrays is another huuuge leap in solar tech. the QDs are able to absorb much more solar energy than a standard solar panel to do the increased surface area the QDs provide to catch sunlight. i suggest looking into the technology before dismissing LEDs. whenever it happens, it will def compete with a 1000w hid in YIELD.

 

[PetFlora]

Knowing what I know now, I would not buy any of the LED light systems currently being offered, and here's why.

For one thing, the lack of heat presents a problem for anyone whose day temps are less than 68 degrees.

Changing LED bulbs is not user friendly. Once the bulbs lose their values, and the blues will do so a lot sooner than the reds, what do you do? Assuming the mfg will replace them, at what cost, and how long a turn around time?

I am running a side-by-side CFL vs LED (well sort of). The LED is a UFO 90. The CFL side uses a 4 bulb Lowes Vanity fixture. It had the benefit of 950 watt equivalent. As you might expect, the plants are fuller on the CFL side. While I am not unhappy with my LED yield, I know I will do much better now that I understand the strain dynamic- it is best for shorter plants or SOG.

I paid $370 for my UFO. In both grows I had a transformer blow, but Sunshine Systems replaced them under warrantee.

You can now buy regular screw in 300 watt equivalent CFLs at Lowes for under $15! You can buy a 4 bulb Vanity fixture for under $20, and 26/43 watt CFL (soft and brights) for less than $8 each. CFLs don't generate so much heat that a closet grower should be concerned. If you can't vent, don't get the 300s.

G2led lights are white, not quite full spectrum. Bulbs are user replaceable, but guaranteed for 5 years, the fixture 30 years!

 

[PetFlora]

What We Need Is a Real World test

What We Need Is a Real World test

Reflecting (no pun intended) back on my almost completed journal (CFL v UFO 90), and learning a ton about lighting since beginning it, I realize my test, and every LED test I have seen, are not "real world" tests.

I admit, for many of you, your interest is not so much about 'max yield', or even highest quality, it's about space and stealth. But wouldn't it be nice to have a "real world" test? And I do not think that test is as simple as watts vs watts.

From what I gather from reading the lighting threads, the reason light knowledgeable growers say you need a minimum of 600 watts is because although it is only 200 watts more than a 400, a 600 outputs 90K lumens (almost double a 400), AND, that is the minimum needed to get a good balanced light spectrum, assuming the ballast is NextGen quality, and a hood comparable to a SunSystemII.

Now, which current LED company's light compares to this 600 watt set up? Let the manufacturers know if this is what you want to see. Then, we will have ourselves a real world test.

I am pricing out a 600 system using a Hortilux 600, SunSytemII hood, and a NextGen ballast. Any LED companies want to donate a comparable light for my next grow journal? I will be using a lowryder/bubble X. Max height is said to be 2 ft, which is mos def in LEDs ideal range.

 

[MedicalMan]

Take a look on grasscity, look for a guy under the alias punjammer - a mate of his is pulling 2lb from 4 x 180 LED... that's 1.2g/w.

He's running a total of 50-60 180's.

 

[watson540]

The cost for the computers that put man on the moon was well into the millions. All those computers combined couldn't match a new $1200 iMac. As LEDs go from bleeding edge to leading edge to industry standard to yesterday's news, prices will drop accordingly.

you are VERY mistaken on that point man. The cost for computers that CAN go into space and have a GUARANTEE to last, and withstand all of the forces and RADIATION in space..is still in the MILLIONS..

and NO AN IMAC WOULD NOT MATCH IT. cuz space shuttles computers were built to LAST and WITHSTAND the elements..look into that field of computers and you will see..a computer that goes into space, and an IMAC are not APPLES AND APPLES

 

[FreezerBoy]

Wow. Way to miss the point entirely. I'm impressed. No idea what you're blathering about but, you go, girl!

 

[BubbleBoi]

Wow. Way to miss the point entirely. I'm impressed. No idea what you're blathering about but, you go, girl!

Interesting thread, my personal opinion having no experience growing with LEDs is that while the technology has came a long ways, its still got a ways to go. Until I see new closet/cab growers coming along and snagging up LEDs rather than hids I'm gonna stick with my trusty HPS. Although, it seams to be getting withen grasp of LEDs being a solid option for smaller (<= 400w) growing setups. While comparing LED to 600w is a good comparison in terms of overall spectrum, there's still plenty of "real world" growers happy with the quality and yield of 400w and 250w cabs. I still look at LEDs as more of a "personal stash" light than grow ROOM light. Current cost, just seams unrealistic to dish out the cash to cover a room with LEDs when a couple larger HIDs will get the job done and have stood the test of time. Be interesting to see where the future takes us though.

Couple pros with the leds that I see as more of cons. While the leds run cool, they still don't scrub the air for you. So although you may not need to cool your light any more, you'll still be using the same amount of electricity on the blower to remove odors and circulate air in cab/closet setups. Another point mentioned, although we typically look at the extra heat in a negative light... without it we'll need to be more mindful of how cool the air is where we grow. Potential problem for attics and basements, having to run a heater could very well close that gap on electricity savings.

One last thought, why on earth do so many people insist on arguing about things that present nothing to lose or gain? Its like the saying, "Arguing on the internet is like racing in the special olympics, even if you win... you're still a retard."

 

[FreezerBoy]

Until I see new closet/cab growers coming along and snagging up LEDs rather than hids I'm gonna stick with my trusty HPS.

Here's your chance to go straight to the source. Ask these guys how they feel.

Sleepy, Hazy, Verdant Green, Blazeoneup

 

[SupraSPL]

Are LEDs misunderstood? Yes and thanks to KNNA for helping explain some of the concepts regarding PPF vs PPFD.

@ Secondtry, I understand your point addressing pn before yield, but all else being equal efficiency and yield have the last word at the end of the day.

 

[SupraSPL]

Due to electrical limitations I flowered with 70w HPS + CFL in cab spaces. 70w HPS is 40% less efficient than 600w HPS. I gladly scrapped the 70s and built passively cooled LED modules based on KNNA recipe. First results ranged from .8 - 1.0 gr/w/8weeks cured and stabilized @ room temp/60% relative humidity. I am very happy with that for starters, especially considering these are not known to be high yielding strains. Resin quality, aroma, flavor and potency were fantastic. UVB was supplemented by a 20w reptile fluoro tube for 3 hours per day.

There is a ton of room for improvement in these results. The girls were suffering from spider mites, rootbound and using peat based soil that was not flushed and being experimentally reused 3 or 4 times without re-amending peat. Added a touch of dolomite lime, but never checked the PH.

The white LEDs I am using are about 107 lm/w while the new R5s are offering 132lm/w. I am using 640nm red while there are high efficiency 660nm reds coming soon.

The 80w grow was cooled and ventilated during lights on by a DC fan 5 watt input power 3 watt dissipation.

Durban Poison trichs:

 

[420atheist]

This thread answered some questions for me. PPFD gives me a number per square meter usually per second or over a day. The reason that number is worthless to us when comparing to HIDs is because it does not tell use what area the light will cover. Lumens per watt does not tell use what area either but it is a common reference. If we know what area a 400 watt HPS will cover we can assume most any light source with the same lumens per watt and a similar spectrum will produce the same yield at the same efficency.

Where Pen and Teller are whispering bullshit in my ear is when these LED web sites state that a 300 watt LED is equal to a 1000 watt HID. But then state a coverage area that is half of what a 1000 watt HID will cover. So how are they the same? They try to convince you that yields will be similar in half the space. Does anyone believe this? Really? Even some of the side by side grows I have read here it seems to not be true. If I need to match watt for watt to cover the same area where is the benefit again?

 

[PetFlora]

I have uncovered a couple of problems with LEDs

Life Expectancy

While I do not know how the bulbs in the UK test compares to what grow light mfgs are using, the 100K life expectancy seems misleading, if not outlandish

http://www.nickhill.co.uk/white_LED_life_expectancy.html

When R/B/W... are combined into one light, replacing blown or exhausted bulbs is not user friendly. Manufacturers need to address this in order to set users minds at ease.

If the individual bulbs are not easily replaced, the entire light becomes useless in approximately 3 years (aver use of 15 hours/day with 15K hours use before sig degradation).

If you believe that tossing an entire LED grow light falls under "the cost of doing business" or that the cost is offset by not needing cooling systems, then by all means pony up your hard eearned cash.

Here's an option, supposedly from the company that started the whole thing

http://ledgrowpro.com/?page_id=1803

 

[knna]

This thread answered some questions for me. PPFD gives me a number per square meter usually per second or over a day. The reason that number is worthless to us when comparing to HIDs is because it does not tell use what area the light will cover. Lumens per watt does not tell use what area either but it is a common reference. If we know what area a 400 watt HPS will cover we can assume most any light source with the same lumens per watt and a similar spectrum will produce the same yield at the same efficency.

Where Pen and Teller are whispering bullshit in my ear is when these LED web sites state that a 300 watt LED is equal to a 1000 watt HID. But then state a coverage area that is half of what a 1000 watt HID will cover. So how are they the same? They try to convince you that yields will be similar in half the space. Does anyone believe this? Really? Even some of the side by side grows I have read here it seems to not be true. If I need to match watt for watt to cover the same area where is the benefit again?

Exactly. PPFD only says the light density level on a given point. It strongly depends of the distance to the lamp, that affects too the coverage.

As you raise the lamp, coverage is larger, but light density (PPFD), lower. The fact is current led lamps on best cases can get a PPFD a little below HPSs but getting similar perfomance (due the higher spectral efficacy) for a coverage double per watt burned. And mostly, less than double, meaning 300W of good LEDs can equal on best cases to a 600W.

On the other hand, brick style LED lamps usually have lower perfomance than that, due they dont distribute the light much better than a HPS does, and that cost efficacy: the more even the light distribution, the higher its efficacy.

Although there is other factors in play, thats why I was putting emphasis on PPF (absolute emission of the lamp) as the parameter that can inform about its potential, or to compare it with other type of lighting.

I have uncovered a couple of problems with LEDs

Life Expectancy

While I do not know how the bulbs in the UK test compares to what grow light mfgs are using, the 100K life expectancy seems misleading, if not outlandish

http://www.nickhill.co.uk/white_LED_...xpectancy.html

When R/B/W... are combined into one light, replacing blown or exhausted bulbs is not user friendly. Manufacturers need to address this in order to set users minds at ease.

If the individual bulbs are not easily replaced, the entire light becomes useless in approximately 3 years (aver use of 15 hours/day with 15K hours use before sig degradation).

If you believe that tossing an entire LED grow light falls under "the cost of doing business" or that the cost is offset by not needing cooling systems, then by all means pony up your hard eearned cash.

Here's an option, supposedly from the company that started the whole thing

http://ledgrowpro.com/?page_id=1803
Yesterday 01:16 AM

LEDs usually dont have a total failure (although it happen), but a light output loss with time. Usually, useful life of lamps is set at the time they falls below 70% of initial emission. But for horticultural applications, usually useful life used is time to reach 80% of initial emission (thats why HPSs are replaced way before their stated life).

Although degradation of output with age has largely improved on last years, its still far from the 100Kh stated for many manufacturers (usually, the less professionals; no any large LED manufacturer states it). Serious manufacturers are offering detailed info of expected lifetimes (times to reach 70 or 80% of initial output) depending of the operating conditions, mainly heatsink temperature and current. Best LEDs running not too hard (current) and with a good thermal path, so they run cool enough, can reach a useful life (80% initial output) as large as 60Kh, that is a lot, but far from 100Kh. But in the most usual conditions, its difficult to find a LED that reach 40Kh, most of them are in the 25-35Kh range.

Not 100Kh, but 30Kh is yet a very good lifetime, near 7 years of continous use at 12h a day.

The problem is this lifetimes are of very good, reputable brands LEDs. And only valid for surface mount ones. Not so good brands LEDs may have way shorter useful lifes, and bad ones, as shorter as 10Kh, less than a fluorescent and only a little over a good CFL.

Through hole LEDs, the typical low power 5mm, and worst yet, the newer powerfull ones, typically have very reduced useful times. DOE (deparment of energy of the US) carried several studies on this topic, resulting on no any of them reaching 15Kh at 70% of initial output. More yet, many of them not lasted 1000h for that figure.

Through hole LEDs are very cheap to produce, but generally they are low efficiency devices and almost always, very short lived (in the sense of light loss). Dont get a lamp that uses them, all of them I know are simply crap. (Included those of the last link)

 

[420atheist]

The treehugger in me wants to reduce my carbon foot print but these LEDs are not what they are advertised to be. Looking at the lumens per watt figure for LEDs from sources like Mouser it seems clear to me that a 300 watt LED has no chance of getting close to what a 1000 watt HPS will do. Aside from a slight advantage of being more directional I'm not seeing any advantage.