COB spectral research microcab

It looks like a soil issue rather than a lighting issue.

Also, I have noticed that side lighting on all the cobs is next to none, but I love the output pattern! This is why I think reflectors are sort of pointless for cobs.

churchhaze said:

It looks like a soil issue rather than a lighting issue.

Also, I have noticed that side lighting on all the cobs is next to none, but I love the output pattern! This is why I think reflectors are sort of pointless for cobs.

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Nah..one part of plant is perfect green..part right under cob is torched. The bubba on the left hasn't been fed much and under watered a few times....that one is nutrient deprived a bit. The other is green as can be..

I dunno about reflectors being pointless though...
Wouldn't want to run cobs in a large area without them. Just like small leds...reflectors make a big difference in ultimate efficiency.

Is it only me who has never experienced bleaching due to light? I've been dealing with a lot of leaf scorching from burns, but never turning yellow. They stay green up until the point of turning black. I keep hearing about it, and trying to figure out why only certain people report bleaching.

I wonder if it has to do with my nutrient formula being on the upper end of suggested iron levels (5ppm on a scale of 1-5ppm). Iron is used along with sulfur to make the protein ferredoxin, which is used in photosystem 1. This has always been my best guess to why I see some led growers experiencing light bleaching.

http://en.wikipedia.org/wiki/Photosystem_I#Iron-sulfur_complex

That aside, do you think that 2700k is a loser? I'm wondering if my 3000k 80cri vero has been why I've experienced more than usual stretch during the first few weeks of 12/12. (finally stopped...). I'm starting to think I should have listened to MrFlux and just got all 4000k straight from the beginning. Maybe the 4000k would work better for the stretch period, but then the 3000k cobs could be used for late flowering? (sorry to thread jack!! lol)

Positivity said:

Nah..one part of plant is perfect green..part right under cob is torched. The bubba on the left hasn't been fed much and under watered a few times....that one is nutrient deprived a bit. The other is green as can be..

I dunno about reflectors being pointless though...
Wouldn't want to run cobs in a large area without them. Just like small leds...reflectors make a big difference in ultimate efficiency.

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40w of light, from one led source like a 3590 or 3070, within 2" to 3". That's a whole lot of light...really close. I would be shocked if a nutrient regime could make a plant endure that amount of light with no bleaching/light burn.

The dead leaves on the right plant started bleached. Then eventually dark yellow and necrotic. It says a lot though I think that it can take so much light before doing that. Only in the more extreme cases does it seem to happen with white.

Can't say at all if 2700k is a loser. I'm actually kinda bummed the results are skewed from the size of the space. But looking through the canopy in the more desirable lighted areas...I still see lots of room for spectrum improvement. But it may be part of a great base

Environment is a far cry from this....coco kush outside. The smells it makes outdoors..and resin quality/quantity..is the end goal.

It just goes from healthy green to black burn marks... and burning weed smell (the leaves kept growing into the cobs...)

It's intense enough to burn, but didn't turn yellow or white before that. I'm near convinced that something about leds increases the requirement for iron in the plant.

Positivity said:

40w of light, from one led source like a 3590 or 3070, within 2" to 3". That's a whole lot of light...really close. I would be shocked if a nutrient regime could make a plant endure that amount of light with no bleaching/light burn.

The dead leaves on the right plant started bleached. Then eventually dark yellow and necrotic. It says a lot though I think that it can take so much light before doing that. Only in the more extreme cases does it seem to happen with white.

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I wouldn't doubt I could use more iron...interesting...lol...

But if normally I don't need more iron do I really want to increase it? Any adverse effects to using more iron?

Best way to supply it organically? Long term release or short more often? I do have some langbeinite...sul po mag...but I usually hesitate to up the mg

I need to research that a bit when I have the time

Just shooting the shirt on lighting.....something to ponder even if just for a sec

I use iron sulfate, but I'm not known for my organics... haha. I use raw salts and hydrobuddy to design hydroponic formulas. Been doing it for about 5 years now with success, so I see no reason to go back to retail bottled nutes.

Yes, Iron will antagonize the other cations, particularly the +2 charge ones like Mg++, and Ca++.

Keeping it below 5ppm in a dwc system will guarantee it doesn't antagonize... Hoagland formula (used mostly in research studies) has a range of 1-5ppm according to wikipedia. I design all my formulas at 5ppm. (and reference hoagland formula for my own formulas frequently)

I don't know how to control that in soil. I would imagine many soils are high in iron without the user even knowing. Soil is too hard for me. The best way to get more iron would likely to be to use less lime. I don't think you really have enough fine control in soil. The best you could do would be to feed 100mg to plant that has bleaching and see how it responds maybe.

Score one for hydro..definitely has it's benefits. I still enjoy the organic way but it does fluctuate in results. By reusing soil and learning what and how much to input I'm getting a lot more consistency nowadays.

Quick reading...

Ahah! I have noticed running higher light intensities has resulted in leaf chlorosis a bit. Iron to the rescue! But first I may have too much phosphorous in the soil...ph may be off...too wet a medium...yes soil is challenging..lol.

But too little iron in soil is rarely the problem. Last grow coco stayed green all the way, no problem. Bubba lightened up in brighter areas...more iron was needed for that particular plant. Or just less light intensity. Or just accept the slight bleaching..

One bonus to extra light intensity though...buds substantially bigger than outside on same size plant.

One funny side note....
I haven't been testing soil ph recently...took a break. My last runs were in soil with a ph of 4.8 - 5....ouch! Some truth to living soil working regardless of ph. That's being corrected now with a 3 way Steve Solomon lime mix of oyster, lime, and gypsum.

Alright. Decided on the 4000k 3070s I had...plus 4 670 cree photoreds. Couldn't resist..

See how this goes. Should have a better spread of light now. Still suboptimal environment in a lot of ways but see what happens.



May get back to 2700k later...

Bone meal and blood meal would be some easy organic sources of iron. My 2 cents

even my chinese WW/R combo gave one plant standing in the middle 3 albino bleached tips. Completly green besides that.
I raised the lights and (dont know how long) later it was gone/ hidden

edit: but my light is symmetrical and other plants were unaffected, so I think it might be straindependant

@Positivity good job!

my 2cents is that if you had more headroom for the 3590 you could do a single point source. They shaded each other getting to close to source and the environment venting was probably insufficient. A few environmental changes and those would have done even better. IMO those plants looked great just got a bit light sick. Im thinking maybe excessive humidity caused a hay smell? or maybe when light sick this is a response also... (thinking aloud)

I like your new take with running 3070's and some red. I have a small cabinet like that and your making me want to fabricate a clone cab w some 6000k vero.


I didnt expect to have to keep my LEDS at least 8" -18" away tbh... the light bleaching is actually a good sign that you have sufficient intensity and penetration. I get it all the time running HPS in the cabinet.

KILLER THREAD.

lax123 said:

even my chinese WW/R combo gave one plant standing in the middle 3 albino bleached tips. Completly green besides that.
I raised the lights and (dont know how long) later it was gone/ hidden

edit: but my light is symmetrical and other plants were unaffected, so I think it might be straindependant

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Interesting. Is that pic the one you speak of, with that tiny little triangular spec of color change at the tip?

we just did an straight RO feed for 7 wks + 8 wks flwr, and got burnt tips too. bit darker though. but super green, top to bottom glossy to the finish.

the tips are noticeable though, think it was the soil or the light?

rockin' a china led panel 400W plus suppin' T5s. height ..was 10 to 16 inches 18 at most, about 12 on average, and she got rotated the least for a couple. i guess i should have rotated more, lifted light, or soils high power. although we use less rock than most organic guys and just dialled back most other things to dial our girls in, and aren't even using leaf mould or a couple other things quite yet (gypsum, zeolite, our own compost, etc)

even two, 3 nodes down got it, see?

oh, btw we use coco and not peat.
( https://www.rollitup.org/t/the-dons-organic-garden.815786/page-22 )

Sold on a DIY project though. the first of several maybe. i thought you guys were all crazy at first! haha but now i see you guys are on another level.. informed, on the way to a more efficient style the people never seen.

BIG UP!

@Positivity Now that panels looking real proper! Would we be able to squeeze a computer fan or two in there somehow, even on the floor or by that pipe hole, to help circulate air in that bad boy?! Those girls are gonna go ham in there now! think you'll need a plan for triacantanol /reducing nodal spacing?

Either way, I can hardly believe what you cats pull off in such small spaces. Nor can I hardly wait to dial in the 40x80 inch space we got. and this cob research and diy panels will be a key. so thanks. 2 days ago i thought my bro had gone mad, linking me to a forum with all these crazy parts! haha, now I'm seeing what you guys are about, its smart.

forgive me if this is elementary to you bruh, but thought it might help.. from another forum i been reading since yesterday.. diy 5v fans for cheap:

link:
http://rollitup.org/t/diy-led-cree-cxa3070.789575/page-9

abiqua says:
"Here is a neat little fan voltage control circuit for $5-10 in parts.
Uses a LM1088Ti adj chip [which has a lower voltage dropout than the LM3xx's] and kicks the fans on @ 5v and then you set with a potentiometer."

Way to pioneer, peeps. Blaze on.

Interesting. Is that pic the one you speak of, with that tiny little triangular spec of color change at the tip?

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yes the text above the pics refers to the pic
I was searching for what could be the cause and found pics similar with the description that that is lightbleaching. Im not a very experienced grower, could be something else I dont know of.

the tips are noticeable though, think it was the soil or the light?

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I havent read anywhere that albino tops could be caused by nutes, I guess im the wrong person to ask something like that

After all that talk about how my plants don't get light bleaching, my pH was too high for a day and got a bunch of bleaching by the lights. I guess what I meant originally wasn't that my plants don't have problems, it's just that I've always thought they were based on deficiencies.

@DonTesla
Building lights was kinda crazy...lol. Using stars at 1.6w each...80 of them..that was a lot of work and I caught myself feeling crazy a few times.

But these cobs which can run 10w - 150w....these are the real deal. Very easy to work with..low stress.

I'm not very worried about bleaching. It was expected with so many lumens coming down so close. Been growing with leds for a while so I have a good feel for it. Red and blue led lights bring it on much easier...one of the first signs to me that the lights weren't balanced spectrally well enough. And yes...some strains are much more prone to it than others.

Triacantanol? I always thought it would increase stretch. But that's just based on its reputation of being a growth stimulant. Snow storm ultra is mostly tria isn't it? So you say it can reduce stretch? Interesting..

My environment in the mini cab needs some attention. It's just a fun side project though so no rush. The room is a bit too small for these big leds...more suited to small stars. Hopefully I'll be able to do this in a little bigger proper area one day. But I do need to get on another fan in there pronto...probably the biggest problem now that I've gotten a better spread of light.

Build one! These things rock and are actually fun to build now that only a few leds are needed. Line them up down your 80" space and witness light nirvana. Cxa 3070 3000k...don't veer to far from there...maybe bridgelux vero 29 or 18 4000k as a more cost efficient version.

my vero 18 3000k and 2700k are doing awesome positivity. I like your experiments here. I need bigger tents also. Boss (wife) says yes. The led tent impressed her actually. Thats hard to do. LOL

Positivity said:

@DonTesla
Building lights was kinda crazy...lol. Using stars at 1.6w each...80 of them..that was a lot of work and I caught myself feeling crazy a few times.

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Thats not crazy, thats just mad dedicated. lol. how else would you have become a "Cob Coach" right?

Positivity said:

these cobs which can run 10w - 150w....these are the real deal. Very easy to work with..low stress.

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Yea these sure seem like THE WAY. could i run a dimmer for each spectrum? So as they progress through cycle lights can "duplicate nature"?

Positivity said:

Triacantanol? So you say it can reduce stretch

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Yea bro! Best source i know of is pure Alfafa brewed in a tea (just soaked).. thats what all the organic guys seem to use for their nodal spacing anyway. Im definitely trying to stack now. last round went on a vaycay and had the girls lank out a bit more than i wanted to see. Dam thing is you gotta hit them in the first 2 weeks of flower with it, thats all. exactly when i was gone.. or mix it into the soil but then it HAS TO COOK. at a 0.25% of total volume ratio to be safe and sound.. my bro DonPetro is even nicer and more knowledgable than me haha he will be happy to talk alfalfa or anything to do with cannabis..

Positivity said:

Build one! .. Line them up down your 80" space and witness light nirvana. Cxa 3070 3000k...don't veer to far from there...maybe bridgelux vero 29 or 18 4000k as a more cost efficient version.

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Duly noted..Now to up my driver, spectrum, and heatsink knowledge a little more, THANKS PIMP!! !!

(and you're right, bud, it is a rare growth hormone, but it promotes efficient inter nodal growth, aka a lotta growth in a compact zone!)

So the 4k has been working great..

Put 7 sour diesel IBL straight to flower. The 4 bushiest were males unfortunately, the three spindly ones female. Not sure what happened there. See how they go anyways..

The major thing I notice...flowering is sloooowwww without the flower trigger. Will need to make another of those...I've been completely spoiled with rapid flower onset.