Led's light bleaching?

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Originally Posted by Douglas1

It is the light! my plant showed very similar symptoms to yours, but got much worse as time progressed because, not only did I think it was nute burn from too rich soil or something, and so did not fix the light issue until the girls were pretty much torched.. but my plants were also very small when I introduced them to two 240's flowering angled in on either side, and the 240veg over head.. needless to say, 350watts or so of true led consumption.. was a little overkill for the youngsters.

what has helped me now, was switching them all over to coco/pearlite mix, so I can get them nutrients quickly, and I know for certain that its not the soil burning them. and mixing up a foliar feed with micronutes, rhizotonic for the roots, and nitrogen.. I also turned off the two flower panels and put the veg about a foot and a half up from the plants. while the ones in pots are recovering slowly, the two in hydro are going full bore..

It's good to know someone else has had this problem, though its a good problem to have really :)


weezard, like I said, they had not been fed at all. I considered the soil being too rich, but the coco plants and the hydro girls all showed the same symptoms until I changed the lights. now the hydro plants have shot out new leaves, and the coco ones are slowly recovering. I planted a new seed though a week or so ago, and it's already outgrown the potted ones.. so something has changed for the better I think.

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Thanks for the feedback, Douglas1, very helpful and encouraging. The more I think about your comment that this is a good problem, the more I begin to see the light. All it takes, I think, is a simple strategy change. Rather than start the plant up high and lower it as the colas develop, I'm going to start the plant down low and let the colas stretch up into the light. This is testament, tutorial, and cautionary warning to others about the penetrating power of the 240W Blackstar vegger. I've carefully read everything I could find about this light (including a grow journal where a guy pitted a 240W Blackstar vegger against a 500W LED competitor) and by all accounts this light is universally underestimated. It just does not look all that powerful, and the intuitive reaction upon first seeing it in operation is to place it about 18" above the canopy. Judging from its effects on our plants, however, this is much too close (and inefficient and dangerous) for such a deceptively powerful light. I should back up and state that my DWC plant (RIP) was trained into a magnificent 2'x3' SCROG, and my hempy plants were flattened with LST into ~2 sq. ft. SCROG-like bushes. This shaping could definitely affect distances, but my ultimate point is the 240W Blackstar vegger is not a simple light. It has a learning curve, and I suspect when we as a user community finally crack its code, it will prove capable of some amazing production rates. Anyway, at this point, just an educated guess...

Ill try to explain why its more than you think and not that simple.
However, plants are frequently seen with foliage of a variety of other colours from shades of red, brown, purple through to black. These colours are caused by other pigments such as betacyanins and anthocyanins produced in response to environmental stress, as a mechanism for filtering intense sunlight or your (led) or as the endpoint of selective breeding of desirable cultivars. These pigments are incidental to photosynthesis, but may well only be produced in plants grown in the strongest light especially with a high blue and ultraviolet content. MASS..... I'll ask you a Q?
I have all these colors in my plant leaves do have deficiency or am i intentional promoting stress training to a xx female f2 with light and environmental training being the key tools to achieve this with no chemicals......?

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Originally Posted by Native¥organicfarmer

Personal Opinion,
its not the thread its the law.......
yea at the frequency of led alone does not promote mass,
but in your case bleaching and a abundance of unused output with 130 watt diodes.
unfortunately led is not comparable to mh or hps for mass.
yes more beneficial at certain frequency and placement in garden as supplemental lighting.
light mass created by either of us only penetrates 3 foot max.
with canopy management yes great results can be achieved but,
the rules of biology dont change.

So in short the only way to achieve true mass is to create it..........
and with the sun 5,000 lumens per sq inch how do you plan on achieving this with led...... Im ready to learn,
i wont argue just run all of them, great results.......

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I don't understand your argument.. are you saying that because mh lights put out more light energy they will always grow plants bigger and faster? the whole idea led's is targeting specific spectrums, so that huge amounts of energy is not wasted on useless wavelengths. I started with one light, and I liked it so much I bought two more, they run cooler, quieter, and on less electricity than metal halide lamps. they bleached my plants because I had way too much on way too little green.

I think you are saying that different colored leaves require different wavelengths in your second post? Maybe it's too late and I'm not thinking clearly but that was what I got.

the 240watt veg model is mostly white diodes, with some blue and red and uv.. so, it's not missing any magical wavelengths. I asked the company why this was, and they said that the white diodes more efficiently provide blue spectrum or something to that effect.

the blues are what you need for mass in vegging, reds for mass in flower. I have two flower panels for that. for 300 watts of led, I'm getting results similar to a 600w mh. and its fact, I've seen it myself.

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Originally Posted by Hataman

Thanks for the feedback, Douglas1, very helpful and encouraging. The more I think about your comment that this is a good problem, the more I begin to see the light. All it takes, I think, is a simple strategy change. Rather than start the plant up high and lower it as the colas develop, I'm going to start the plant down low and let the colas stretch up into the light. This is testament, tutorial, and cautionary warning to others about the penetrating power of the 240W Blackstar vegger. I've carefully read everything I could find about this light (including a grow journal where a guy pitted a 240W Blackstar vegger against a 500W LED competitor) and by all accounts this light is universally underestimated. It just does not look all that powerful, and the intuitive reaction upon first seeing it in operation is to place it about 18" above the canopy. Judging from its effects on our plants, however, this is much too close (and inefficient and dangerous) for such a deceptively powerful light. I should back up and state that my DWC plant (RIP) was trained into a magnificent 2'x3' SCROG, and my hempy plants were flattened with LST into ~2 sq. ft. SCROG-like bushes. This shaping could definitely affect distances, but my ultimate point is the 240W Blackstar vegger is not a simple light. It has a learning curve, and I suspect when we as a user community finally crack its code, it will prove capable of some amazing production rates. Anyway, at this point, just an educated guess...

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I'm happy with it, learning curve for certain though.. it seems like the hydro girls handle the high amount of light better than the potted plants.. not sure why that is.

something else that's cool about these lights.. I can run two at once, and not worry about venting at all, no fans no in/out. just co2 piped in at the right ppm. no heat problems, and opening the door occasionally to check em lets out the humidity.

Disadvantages,

High initial price: LEDs are currently more expensive, price per lumen, on an initial capital cost basis, than most conventional lighting technologies. As of 2010, the cost per thousand lumens (kilolumen) was about $18. The price is expected to reach $2/kilolumen by 2015. The additional expense partially stems from the relatively low lumen output and the drive circuitry and power supplies needed.
Temperature dependence: LED performance largely depends on the ambient temperature of the operating environment. Over-driving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life. This is especially important in automotive, medical, and military uses where devices must operate over a wide range of temperatures, and need low failure rates.
Voltage sensitivity: LEDs must be supplied with the voltage above the threshold and a current below the rating. This can involve series resistors or current-regulated power supplies.
Light quality: Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can cause the color of objects to be perceived differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism,red surfaces being rendered particularly badly by typical phosphor-based cool-white LEDs. However, the color rendering properties of common fluorescent lamps are often inferior to what is now available in state-of-art white LEDs.
Area light source: Single LEDs do not approximate a point source of light giving a spherical light distribution, but rather a lambertian distribution. So LEDs are difficult to apply to uses needing a spherical light field. LEDs cannot provide divergence below a few degrees. In contrast, lasers can emit beams with divergences of 0.2 degrees or less.
Electrical Polarity: Unlike incandescent light bulbs, which illuminate regardless of the electrical polarity, LEDs will only light with correct electrical polarity.
Blue hazard: There is a concern that blue LEDs and cool-white LEDs are now capable of exceeding safe limits of the so-called blue-light hazard as defined in eye safety specifications such as ANSI/IESNA RP-27.1â??05: Recommended Practice for Photobiological Safety for Lamp and Lamp Systems.
Blue pollution: Because cool-white LEDs (i.e., LEDs with high color temperature) emit proportionally more blue light than conventional outdoor light sources such as high-pressure sodium vapor lamps, the strong wavelength dependence of Rayleigh scattering means that cool-white LEDs can cause more light pollution than other light sources. The International Dark-Sky Association discourages using white light sources with correlated color temperature above 3,000 K.
Droop: The efficiency of LEDs tends to decrease as one increases current.

eventually someone will understand what im saying..............

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Originally Posted by Douglas1

also.. how do you like growing in straight pearlite? my coco pearlite mix is roughly half and half and I love it.. seed I started straight in the mix and fed 250ppm until it had some true leaves, than 500ppm currently.. and crap, it's the fastest I've ever seen for this stage of development.. dwc you have a waiting period until it puts down roots.. this just takes off from the start.

I don't like how much gnats like it though.. you have that problem with pearlite?

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I love growing in straight perlite, and I totally agree with you about DWC. My DWC plant was clone from popcorn-bud cutting taken last October, and it took damn near forever to get through the bubble cloner into the final 5-gal DWC tank. My success rate was one in twelve cuttings. Most of the cuttings were lost transplanting into various media including perlite.

Nowadays I clone with Rapid Rooters. As soon as the clones pop roots, the RRs go straight into 100% perlite and the clones get a thorough watering with full strength nutes (SensiGrow AB). Growth rates with this approach are incredibly fast. These two photos are of the same clone taken just shy of 5 days apart.

Attachment 283166Attachment 283167

Veg growth was equally impressive. Incidentally, the 2nd picture was taken while euthanizing the clone, which was a backup. The success rate cloning with RRs is a solid 100% so this backup clone was not needed. The growth rate of the kept clone was even more impressive.

One thing about straight perlite, nutrient uptake is so blazingly fast that daily feedings of full-strength nutes are required. If even a single day is missed, deficiencies start kicking-in immediately. The reward, of course, is blazingly fast growth rates. It still amazes me how heavily and how fast the plants feed in straight perlite. I've never had to flush with water. Doing so would probably severely starve the plant.

One big goal in using straight perlite is to keep organic material in the media as low as possible specifically to prevent infestations, so I've avoided adding coco or any other organic media (the RRs are the one exception). Thus, knock on wood, I've never had any problems with fungus gnats. Occasionally, I'll add about 1 oz. of h2o2 (hydrogen peroxide) per gallon of nutes to knock-down algae, pests, and other accumulated organics in the perlite. If you're using organic nutes, I'm not sure if using h2o2 is good advice because it oxidizes many organic compounds.

I have yet to grow from seeds, but my hunch is the same RR->100% perlite + full strength nute approach will work equally well for seedlings. One thing's for sure, I'm not letting any future seedling of mine anywhere near the 240W Blackstar vegger.

Bottom line, I've tried DWC, aeroponics, and several vermiculite/perlite hempy bucket mixtures, and overall, the 100% perlite hempy bucket has owned all of them.

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Originally Posted by Hataman

Thanks for the feedback, Douglas1, very helpful and encouraging. The more I think about your comment that this is a good problem, the more I begin to see the light. All it takes, I think, is a simple strategy change. Rather than start the plant up high and lower it as the colas develop, I'm going to start the plant down low and let the colas stretch up into the light. This is testament, tutorial, and cautionary warning to others about the penetrating power of the 240W Blackstar vegger. I've carefully read everything I could find about this light (including a grow journal where a guy pitted a 240W Blackstar vegger against a 500W LED competitor) and by all accounts this light is universally underestimated. It just does not look all that powerful, and the intuitive reaction upon first seeing it in operation is to place it about 18" above the canopy. Judging from its effects on our plants, however, this is much too close (and inefficient and dangerous) for such a deceptively powerful light. I should back up and state that my DWC plant (RIP) was trained into a magnificent 2'x3' SCROG, and my hempy plants were flattened with LST into ~2 sq. ft. SCROG-like bushes. This shaping could definitely affect distances, but my ultimate point is the 240W Blackstar vegger is not a simple light. It has a learning curve, and I suspect when we as a user community finally crack its code, it will prove capable of some amazing production rates. Anyway, at this point, just an educated guess...

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Ayah, late night senioritis, I meant 240W Blackstar bloomer, not vegger.

I’ve had the same thing happen, except my flower lights are Blackstar 180w... I’m new, so I thought I’d probably made mistakes, but it seemed odd that things went wrong within days of changing lights.

The same thing has happened on my new grow. However, I have some plants grown from seed and some from clones under the same lights. The clones are yellowing, but the seed plants are fine! In fact, I have one seed plant and one clone in the same pot, showing different results. I wonder if clones are less hardy. I've tried all the iron /magnesium /sulphur deficiency stuff.

Please keep posting your findings, I would really like to get this sorted.

So does it seem like light bleaching? Im having the same issue with the blackstars and its driving me nuts

yes! light bleaching it was, are you using veg or flower panels? I have my 240w flower panel about a foot above the plants now, and they are all doing much better. I think running the veg panel from 2ft or more would be good for this stage, then gradually lowering it as the plants mature