tired of adjusting cfl lights. led time

"Chip on board" and "lumens per watt." COBs appear to be the next generation. Higher LPW, lower labor costs to assemble because it's one chip with dozens of diodes on it. Not individual diodes mounted on a large white backboard. (Downside to me is that it's more light from a smaller point. I lean towards less light from more sources. They're probably great for large grow operations. For a handful of plants like I do, I like having the lights closer, spread around the plant, more coverage and diffusion.).[/QUOTE]

thanks for the clear answer.

95'ZR1 said:

Lumens do not mean everything.

look at a hps light it has a ton of lumen output but in the wrong spectrum which is why 250-300w of good leds can outgrow a 600whps. You really need to stop looking at l/w. A green led might put out 250lm/w are you going to use that one?

it is all about spectrum. This is the exact reason many of us use the 3070 or 3590 but then supplement with a few 450-480 and 630-670nm leds. I grew the same exact plant twice one with 52watts of 3000k cxa3070 the other with 52w of 3000k 3070 and added 15w of 670nm and 5wof 630 and the one with ssupplement lighting was a much better yeild. And now I'm using 730nm for 8min at lights out and am getting the same yield but taking roughly 10days off my flower time.

Imo with leds it's all about spectrum.

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Can we get pics of those grows? And specific numbers as to what a "Much better" yield is, so we can rule out statistical standard deviation, etc.

Don't have any pics.

just white was 45.4gr
white with red 63.6

95'ZR1 said:

Don't have any pics.

just white was 45.4gr
white with red 63.6

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FWIW, when I ran 85w red/blue chinese epi-whatever UFO (Blackstar 135w) I got 90g. When I added 38w of 90 lm/w white (2700k in flower) I got 150g.

My comparison suffers like yours does. I didn't remove red/blue watts for a more apples/apples comparison. But, the results are similar.

95'ZR1 said:

I grew the same exact plant twice one with 52watts of 3000k cxa3070 the other with 52w of 3000k 3070 and added 15w of 670nm and 5wof 630 and the one with ssupplement lighting was a much better yeild.

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95'ZR1 said:

Don't have any pics.

just white was 45.4gr
white with red 63.6

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Math time.

The two scenarios you described.
52w = 45.4g
(52w + 20w) = 63.6g


63.6g = (45.4g + 18.2g)

% Wattage increase = 20/52 = 0.38 = 38%
% Yield increase = 18.2/45.4 = 0.40 = 40%.

Also

White 45.4g/52w = 0.87g/w
Red 18.2g/20w = 0.91g/w

You increased wattage by ~40% and got ~40% increase. If spectrum was as important as you say, the increase from the targeted 20w spectrum should be proportionally higher than it is. 0.87g/w and 0.91g/w aren't far enough apart for their difference to be statistically significant, hence you can't take those numbers and say that targeted spectrum is any better. I'm not taking your stated lumen counts into account since I feel they are off since Supra lists his 3070 as getting 139 l/w driven at 700mA [dissipating 25w] so I have a hard time believing that yours gets over 150 l/w being driven twice as hard [and thus less efficiently], and 40 l/w seems overly low for the red diodes, but if you provide me a datasheet proving otherwise I would be happy to crunch the full numbers.

Ace Yonder said:

hence you can't take those numbers and say that targeted spectrum is any better.

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I agree, that particular example didn't demonstrate reds/blues yield more (just as my example adding white didn't prove white yield more. All we know is more light = more yield.). But, it does seem well accepted that cannabis likes more red (and perhaps blue) than any white light produces. Area 51's RW, Astir's lights, ApacheTech.

I think it gets back to how we don't have spectrometers to measure the effectiveness of our whites, and how the spectral curve changes adding reds and blues.

Why's nobody getting exicted about that $40 PublicLabs DIY spectrometer? I think it could be huge! But, the silence indicates otherwise.

95'ZR1 said:

Lumens do not mean everything.

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This is part of your argument is true. While it does not mean everything, it does mean something. If you assume 2 lamps have the same relative spectral distributions, then logic follows that the one with higher luminous output must also have higher photon flux output and radiometric power output.

So maybe lumens by themselves are sort of misleading, but if you're comparing a 660nm to a 660nm or a 3000k white to a 3000k white, the one with higher luminous output will logically have a higher power output as well.

Power output / power input (efficiency) is probably the most important factor when considering a lamp.

95'ZR1 said:

look at a hps light it has a ton of lumen output but in the wrong spectrum which is why 250-300w of good leds can outgrow a 600whps. You really need to stop looking at l/w. A green led might put out 250lm/w are you going to use that one?

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How can you say HPS has the wrong spectrum when it produces flowers so effectively? HPS spectrum must be very good in that case. My theory is that the yellow, amber, and orange from HPS is responsible for its success, and not the wrong color at all, at least for flowering.

I would go with California Lightworks 110 or 220 veg model! I think there 3x3 for veg! I would buy multiples of these to distribute the light were its needed!

I didn't mean hps has the wrong spectrum where it won't flower because it obviously does just fine.

but with a better spectrum you can get away with using much lower wattage or output. Which is why I believe a 300-400 watts of led almost always outperforms a 600 hps.

@church everything you said about comparing 660 vs 660 I completely agree with and the efficiency is what people should be looking at

The lumen output is dead on for the 3070s I used two 3070s driven at aprox. 700 ma which comes out to aprox 7800lumens.

also the red i don't think was an actual 20w of output it was what the leds were rated at.

this isn't the best example since it is a bit overkill on the red vs white. Now in my actual tent I'm using roughly 1.5w of red for every 12w of white and am seeing a noticeable difference so far. I really don't care what the math says i go by what works.

are you saying spectrum means nothing? Or just not as much as most people make it out to be?

95'ZR1 said:

I didn't mean hps has the wrong spectrum where it won't flower because it obviously does just fine.

but with a better spectrum you can get away with using much lower wattage or output. Which is why I believe a 300-400 watts of led almost always outperforms a 600 hps.

@church everything you said about comparing 660 vs 660 I completely agree with and the efficiency is what people should be looking at

The lumen output is dead on for the 3070s I used two 3070s driven at aprox. 700 ma which comes out to aprox 7800lumens.

also the red i don't think was an actual 20w of output it was what the leds were rated at.

this isn't the best example since it is a bit overkill on the red vs white. Now in my actual tent I'm using roughly 1.5w of red for every 12w of white and am seeing a noticeable difference so far. I really don't care what the math says i go by what works.

are you saying spectrum means nothing? Or just not as much as most people make it out to be?

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I think spectrum is very important, I just think we don't fully understand everything about the way the plants use light. For instance, based on several studies I have read, I feel that green light is unappreciated when it comes to photosynthesis (For example, this study: "Green Light Drives Leaf Photosynthesis More Efficiently than Red Light in Strong White Light: Revisiting the Enigmatic Question of Why Leaves are Green" http://pcp.oxfordjournals.org/content/50/4/684.full) so I feel that while red and blue may look like the best colors, there may be hidden benefits to the less obviously utilized colors that are present in white light but not present in straight reds or blues. It's the same reason CFL/fluorescents still have some utility, and why HPS/MH are potentially lacking when it comes to theoretical effeciency in terms of photosynthesis and cannabis development (For example HPS put out almost no UV light, which leads to advantages from using either a combination of HPS/MH or a CMH during flowering, as THC is partially a defense against damaging UV rays). This is why I feel there isn't a larger impact when comparing pure red/blue light to white light. If we could find ALL the necessary spectra we could make a light that truly has no wasted light output, but that is several years down the line.

Another article digging a little bit deeper into the specific effects of green light can be read here: http://www.sciencedirect.com/science/article/pii/S0098847211001924 (the tl:dr of this article is that 510nm green light at PPF300 has the most dramatic postitive effect on plant growth)

as a soon to be led owner, reading this thread has enlightened my thoughts to buy a quality light for the long term. light color concerns me and i can't find the answer to my question. when the led lights are on do they give off a white or red glow. if so, can i control which color to use. thanks

@ACE very interesting articles thanks a bunch for those

@Po boy it depends on which light you get or really what dioded are in the unit.

Most commercial units are using white now but still use reds to supplement so these will give a very slight pinkish color.

thanks for the answer. i'm in a situation where there is glow though the window blinds and white is not as noticeable as colors.

az2000 said:

Maybe @mauricemm can give his opinion. He turned me onto the SMD 5730 corncob lightbulbs.
.

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I saw that thread where the corn lights came up (can't remember what thread it was) and checked out the link provided. Out of curiousity I ordered a couple of the 15 watt, 110 volt, whites. According to my kill a watt they are running at a whopping 2 watts. I'd be curious if you get some, and you have a kill a watt meter or equivalent, what the actual wattage of yours are.

OnlyFractured said:

I saw that thread where the corn lights came up (can't remember what thread it was) and checked out the link provided. Out of curiousity I ordered a couple of the 15 watt, 110 volt, whites. According to my kill a watt they are running at a whopping 2 watts. I'd be curious if you get some, and you have a kill a watt meter or equivalent, what the actual wattage of yours are.

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Ouch! How much light are they putting out? Got any lux meter readings?

Ace Yonder said:

Ouch! How much light are they putting out? Got any lux meter readings?

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Well, not a big ouch, they're less than 3 bucks each and I only ordered three. I could give you umole readings from an inch away or something with an apogee meter, but I don't know if it's worth the effort.

OnlyFractured said:

Well, not a big ouch, they're less than 3 bucks each and I only ordered three. I could give you umole readings from an inch away or something with an apogee meter, but I don't know if it's worth the effort.

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Price aside, 2w is a lot less than even the 7.5 I would have guessed their actual draw at. Was just wondering if the brightness was as dramatically less than quoted as their wattage.

Ace Yonder said:

Price aside, 2w is a lot less than even the 7.5 I would have guessed their actual draw at. Was just wondering if the brightness was as dramatically less than quoted as their wattage.

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The brightness is dramatically less than a 6.5 watt cree bulb. Very dramatically less.

OnlyFractured said:

The brightness is dramatically less than a 6.5 watt cree bulb. Very dramatically less.

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I'd still love to see lux readings from both to work out price/brightness ratios with precision.

OnlyFractured said:

I saw that thread where the corn lights came up (can't remember what thread it was) and checked out the link provided. Out of curiousity I ordered a couple of the 15 watt, 110 volt, whites. According to my kill a watt they are running at a whopping 2 watts. I'd be curious if you get some, and you have a kill a watt meter or equivalent, what the actual wattage of yours are.

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Is it possible you got the 220v bulbs? Maybe @mauricem00 could give his thoughts. That would be too bad if they're really not ~105 lm/w. I haven't received mine yet.

This is the thread you're remembering: https://www.rollitup.org/t/t8-lights-for-growing.850807/#post-11056855

Also: https://www.rollitup.org/t/6500k-led-bulbs-help.851560/#post-11085987