Led's light bleaching?

[redleb]

Well done Hataman. Apparently there's more to this LED business than meets the eye .. The potential looks really good, if not without risk!

Our grow styles are quite different, so i'll play around until get a reliable method. What I am hoping that the Iron content of my Seaweed additive is enough stop the problem. And still maintaining the lights slightly higher for the time being though.

I'm told foliar feeding is a good way to get Iron in quickly.

Keep charting your progress.

redleb Reviewed by redleb on 03-25-2012. Led's light bleaching? on a legal medical grow the panels, (one veg, one bloom 240w blackstars) are roughly 16-18" above several plants, two in coco, two in fox farms, and two dwc.. all of the plants are stunted, all of the plants have dead foliage. Ph is good, temp is good, ppm is good.. several of the plants have white patches on their leaves, like all the color has left. most of the plants cotledons have dried up like a nitrogen defficiency... they have been treated with micronute foliar sprays.. canazyme, Rating: 5

[HipsterDoofus]

--HipsterDoofus, interesting tip about Miracle-Gro. Did you use the All-Purpose version? Makes me wonder if it can be adapted for hydro.

I did use the all purpose version. And I finally got a good pH meter. My soil is incredibly acidic. The difference is clear between the healthy green ones and the yellow ones. All the healthy plants are around 6.6, the yellow ones are all well below that. So that's my next task, to fix the soil pH.

[jmrc00]

Attachment 283893
This is what happened to my plant that was under Blackstar 240 veg/clone about 14-16inches above top. Also I had a 600uv in the same room that was sending off some light and this is what happened in 2 days.

[HipsterDoofus]

Just to update - it really was leaf burn and bleaching on my plants from the led. I moved the plants to natural sunshine for a week and they are recovering nicely. So I've put the blackstar 240w uv back in the box for a while.

[Douglas1]

I'm happy to report I've got three new plants 12" under the 240W Blackstar Flowering light, and all three are growing in fast track mode. The trick was to give the plants additional iron and let them veg for at least a few hours BEFORE putting them under the 240W. This gave the plants enough time to draw-in the iron and transport it to the growing tips.

The photo below is dated 3/17 22:33. I've nicknamed the four plants in the hempy cups Cannon Fodder Clones #1-4 because they were raised specifically to go up against the 240W Deathstar. At this point, I hadn't yet made the iron deficiency diagnosis so the prospects for these clones was basically certain death. The smaller clone in the lower left is a special case I've nicknamed New Runt for obvious reasons--a perfect candidate for the first sacrifice. The plant in the 2 gallon hempy bucket in the far upper right corner is nicknamed Old Runt. As a cutting, Old Runt started out 1/3rd the size of the next smallest clone in a batch of eight, and went on to outroot and outgrow all of them. All eight clones were severely damaged by iron deficiency. At this point, Old Runt has been sitting in the veg box under the 180W Blackstar veg light for about 2 weeks, recuperating from its bout with the 240W Deathstar (if you look close, you can still significant iron deficiency damage). The big lesson here (that I learned the hard way) is move your least valuable plants under the 240W Deathstar first, then slowly work your way down to your star performers.

Attachment 283626

Below, the photo on the left is dated 3/21 18:30. It shows New Runt one minute before being moved from the 180W Blackstar veg light to the 240W Deathstar for a 12.5 hour light cycle. For the previous three days, it has been fed with SensiGrow and SensiBloom with various concentrations of added iron. The plants in the 1 gallon hempy buckets are Cannon Fodder #1-3. They were transplanted on 3/18, and at that time, Old Runt was fed some iron, heavily pruned to remove damaged leaves, and put back under the 240W Deathstar. The photo on the right is dated 3/24 20:54, and shows the same plant, New Runt, after it has received approx. 39 hours of full-bore exposure to the 240W Deathstar at a distance of 12"--plenty enough to leave a "non-ironed" New Runt a smoking ruin. As you can see, not only has New Runt escaped deficiency damage, but it has also put on considerable new growth.

Attachment 283621Attachment 283622

The photo below is dated 3/24 21:08 and shows the 240W Blackstar flowering light positioned 12" above the canopy. You can see New Runt is positioned center left, Cannon Fodder #3 [Bush Baby] center top, and Cannon Fodder #1 [Darth Maulette] center bottom. Old Runt is top right, and top left is Bonsai Mother. This last plant is a special case. She's a sister clone to Old Runt, and I kept her in her 16oz. hempy cup in an attempt to make a true Bonsai Mother out her. Unfortunately, she grew so fast that I lost the heart to prune her just for the sake of keeping her small. As the 240W Deathstar continued to maul my plants, Bonsai Mother's number came up. Initially I kept her 30" under the light, and she grew just fine with zero damage. After I talked to Lighthouse Hydro, I lowered the light to 18". My rationale was the many days of exposure at 30" might have hardened the plant, and she would now tolerate a shorter distance. Wrong. After just a few hours at 18" she began exhibiting the usual damage. About that time, I began theorizing iron deficiency, so I quick ran out to a local nursery, bought some Liquinox Iron & Zinc, and began feeding Bonsai Mother extra iron. Subsequently I've fed her tons of extra iron, and sprayed her leaves 3-times a night with Bonide Liquid Iron, but as you can see, recovery has been slow, slow. To be fair, though, much of Bonsai Mother's weird, stunted appearance is owing to her still being in a 16oz. hempy cup. Getting back to Bush Baby, center top, she was fed with SensiBloom + Bonide Liquid Iron at 1.5 tsp/gallon for about three days prior to her bout with the 240W. Darth Maulette was fed with SensiGrow + Bonide Liquid Iron at 0.5 tsp/gallon approx. five hours before 240W exposure. At this point, both plants have received about 19 hours exposure to the 240W, plenty enough time to cause the damage, and yet both plants are showing zero damage. Indeed, both appear to growing extremely rapidly. Old Runt also appears to be doing quite well. It must be noted, though, she spent several weeks revegging under the 180W Blackstar, all the considerable deficiency-damaged growth has been pruned away, and the plant has received massive cosmetic LST. In other words, the Old Runt you're seeing in this photo is basically a entire new plant. To quickly summarize, with the 240W Blackstar UV (flowering) light:

Plants with no pre-feeding with extra iron: 100% iron deficiency damage rate.
Plants with extra iron pre-feeding: 100% success rate.

I don't know how it could be any more conclusive.

Attachment 283623

Conclusions:

--The main reason I'm taking all this time to write this post is I wanted to undo any damage I might have caused Lighthouse Hydro and their terrific line of Blackstar LED grow lights. I think I've shown to everyone's satisfaction the 240W Blackstar UV light is definitely not causing light bleaching. I've also proven (to myself, anyway) that Lighthouse's recommendation of a 12" distance (or even less) is indeed accurate. At that distance, my plants appear to be growing in turbo mode. I've gone from blindly accepting this light, to doing mortal combat with it, and now loving it like a trusted horse. I'm definitely keeping it, and I'm also seriously considering buying another to replace my 180W Blackstar HO veg light. I'll have to do some further measurements, but my plants appear to be growing faster with 12 hours of the 240W light than 24 hours of the 180W light.

--The 240W Blackstar UV LED light (and probably all flowering LED panels over 200W) require real growing expertise. They are not beginner lights. The margin for error is a lot slimmer, and users must know their plants AND their nutes like the back of their hands. Here are some of the lessons I learned the hard way. The 240W Blackstar UV light:
*is capable of causing deficiencies by inducing too fast a growth rate (ultimately a really nice problem to have).
*requires users to go over their nutes with a fine-tooth comb and clearly identify those nutrients that will go into deficiency under hyper-growth conditions.
*requires a "pre-feeding" period under a less powerful light. The purpose of this pre-feeding is to get all necessary micro-nutes up into the growing tips of the plant before going under the 240W.
*makes it really hard to rehab plants. Growth pressure is so strong that once plants go into deficiency, they find it extremely difficult if not impossible to catch up. Rehabbing, therefore, should be done under a less powerful light.
*requires that deficiency-susceptible plants be supplied with extra nutes throughout the entire time the plants are under the 240W light.
*for nutrient manufacturers, opens up new market opportunities for hyper-growth LED formulations.
*(if your plants go into deficiency) forces the dilemma of deciding between rehab or starting over. Which is better?

In the photo below (dated 3/7 19:34), the upper right plant is Old Runt rehabbing in the veg box after ~36 hours exposure to the 240W Deathstar. Note how all the damage is occurring in the new growth. This is key to the iron deficiency diagnosis. The center left plant is nicknamed Original Clone. It also is rehabbing after ~8 hours exposure. Note how Original Clone is recovering much faster than Old Runt. So much so, the next day Original Clone was put back under Deathstar while Old Runt was left to veg another two weeks. The lower right plant is a sister clone that has never faced Deathstar. Its turn, however, came up and it eventually had to be put down.
Attachment 283624

The photo below (dated 3/17 20:53) shows Original Clone after nine days of flowering under the Deathstar. This is before I diagnosed the iron deficiency, and note how the damage has carried on. Overall growth is good, but the flowering sites are weirdly diminished.
Attachment 283625

In cutting back Original Clone to expose only the healthy, undamaged flowering sites, the plant suddenly shrank to nothing, and I decided to destroy it.

--This is definitely not a sulfur deficiency. The keys to a correct diagnosis are:
*The damage is contained to new growth.
*Adding sulfur does nothing.
*Adding iron works miracles.

--I wouldn't add CalMag to cure iron deficiency as this raises the risks of introducing calcium and magnesium toxicities. Liquinox Iron and Zinc is 0.2% iron and 0.2% zinc. The problem with this is zinc quickly becomes highly toxic, as I found out when Old Runt suffered mass wilting and necrosis after adding a large dose of Liquinox. Fortunately, a thorough flush quickly restored the plant. In my experience with all this, I've found it's best to stick with the plain, unadorned, base nutes, and only add supplements to treat specific deficiencies. After the Liquinox debacle, I switched to Bonide Liquid Iron Plus Micronutrients. Liquid Iron is 5% iron with much smaller percentages of other micro-nutes. This means I can play around with iron dosages without worrying about introducing other toxicities.

--Thanks redleb for the input. The fact that you're experiencing yellowing 10 days into flower tells me I need to keep adding iron throughout the entire grow.

--HipsterDoofus, interesting tip about Miracle-Gro. Did you use the All-Purpose version? Makes me wonder if it can be adapted for hydro.

--Whew, enough is enough. I'll close by reiterating the 240W Blackstar UV is a great light that definitely does not cause serious light bleaching or photo toxicity. In fact, in the hands of an expert grower, it could well be capable of miracles.

Peace out,
Hataman

I don't get it. I'm having the same problem as always, matches your images perfectly, every plant is hit with it. I moved it them all under a less powerful light and rehabbed. Nothing is changing, I fed with a magnesium/micro mix.. no results, fed with epsom salts, no results, fed with an iron foliar.. same thing. I'm about to dump these for a 400watt hps if something doesn't change.. my clients waiting on his harvest which i should have had by now and is still 8 weeks out

[Douglas1]

Well, taking a chance here. I built a 4x2x4 cab and have one 240w flower light mounted. good airflow, spacious, poor reflectivity on most surfaces to try and lower the intensity of the light a little.. foliar fed with "spray n grow micronutrient" (5%zinc 10%iron). last time I wasn't using cal mag, so I'm feeding with that as well now in the res.

Have my two hydro girls and a coco I think is likely a male.. but otherwise my 3rd most hardy plant. I would prefer to use some more sacrificial plants.. but these guys are the ones that bounced back quick enough and I need to get a harvest on the way..

starting bloom today, using flora grow, going to use equal amounts of gro, micro, and bloom for the first week and shoot for 6-800ppm on the smaller one, 8-1k for the big girl with the calmag added.

hopefully the shorter light span, (18hr down to 12) the iron feeding, and the calmag will make the difference.. if not the box will accommodate a 400w hps with no trouble..

how often are you foliar feeding the iron?

[Douglas1]

Well guys, I have some useful information
I was using the gh trio, grow bloom and micro. the symptoms here looked a ton like either iron or sulpher def.. so, I checked out the back of the bottles.. grow actually has none of either.. bloom and micro both have micro nutes.. but grow is primarily potassium and a modest amount of nitrogen.

Seeing this, I thought about the Lucas formula.. which uses one part micro to two parts bloom, and cuts out the grow completely.. basically doubling-tripling my iron, and quadrupling my sulpher amounts in the res.
This coupled with a weekly morning foliar feed of iron has completely halted all of my problems.. Not to mention simplified feeding.. Also no longer need calmag.

The only problem with this now is that I don't have a good way of feeding my soil girls, with hydro I am in control.. with the dirt ladies they are more or less on their own. so, next round I think I'm doing hempy buckets with airstones in their res, and using a screen for canopy managment. should be a pretty simple set up
within a day, all of my plants instantly stopped yellowing

[mr gold]

A big thanks to Hataman and also the input of Douglas1 ! I have been havnig the same problems as Hataman with my led lights and have been doing similar things to try and solve this problem and already had put my plants in a a recovery light room but didnt have the iron deficiency sussed out until reading this great thread. At the very begging of my troubles i thought iron def may be the problem until all different things started to happen and i sorta forgot about the iron !! Any way, i have 6 plants in different stages of growth and have bought a powder (just containing iron) that i have mixed up at half strength to play it safe. I have watered all plants (just now) and also given a foliar feed which i intend to do every day for a few days. My question is did you have to continue adding to keep the iron to the feed for the rest of the grow or just occasionally or not at ?
The box says that it lasts 2 or 3 months with the one dosage. I am growing in BioBizz light mix and intend to grow in coco the next time around as i believe this will be better for nutrient take up. Many thanks for this thread and any words of wisdom that you have learnt since writing this thread. :thumbsup:

[mrdro]

A big thanks to Hataman and also the input of Douglas1 ! I have been havnig the same problems as Hataman with my led lights and have been doing similar things to try and solve this problem and already had put my plants in a a recovery light room but didnt have the iron deficiency sussed out until reading this great thread. At the very begging of my troubles i thought iron def may be the problem until all different things started to happen and i sorta forgot about the iron !! Any way, i have 6 plants in different stages of growth and have bought a powder (just containing iron) that i have mixed up at half strength to play it safe. I have watered all plants (just now) and also given a foliar feed which i intend to do every day for a few days. My question is did you have to continue adding to keep the iron to the feed for the rest of the grow or just occasionally or not at ?
The box says that it lasts 2 or 3 months with the one dosage. I am growing in BioBizz light mix and intend to grow in coco the next time around as i believe this will be better for nutrient take up. Many thanks for this thread and any words of wisdom that you have learnt since writing this thread. :thumbsup:

How did you make out Mr gold after adding the iron? I am having the same issue with 500UV's...lime green on new growth. This started almost instantly...3rd day in.

[mrdro]

See the pictures below,

Attachment 289937Attachment 289938