Led's light bleaching?

[Cyclonite]

Good to hear....I have 2 240watt flower panels. Right now I shut them off and just have some CFLs. I didn't want to impede growth anymore. I raised them to 15" or so. I hit them with extra cal-mag also since I heard thats also an issue. Do u have any tips? I have plenty of experience but this is my first real go with LEDs

[Skihigh]

Although I don't run LED's,I do use perlite,coco and vermiculite. Mix them just about 1/3 each. Maybe a tad more coco in the mix.
The coco offers some organic property to the mix that some of the beneficial bacteria and fungi might take to a little better.
I might be full of crap, but I'm having some fairly amazing results right now. I have used DWC, straight vermiculite, straight perlite, and soil but this mix so far has worked best for me.
My main nemesis growing is heat issues; Mainly caused by a piss poor ventilation system and lack of funds.
Y'all keep up the good work.......J

[Hataman]

Even with 30" of separation, I was still having bleaching problems (albeit much, much slower developing) with my 240W Blackstar UV (bloom) light. Thinking to swap the 240W panel for the 180W light, I called Lighthouse Hydro. The gentleman who answered the phone was quite helpful, and spent about 1/2 an hour trying to figure it out the problem. Ultimately, he was at a loss as to the specific cause of these symptoms, but he was insistent that:
--The symptoms I was describing were not light bleaching, but were more likely some kind of deficiency. With their lights, light bleaching takes the form of a slight lightening of the leaves when they come within 6" of the LEDs.
--30" was way too much separation. For the 240W UV, they recommend 12" above the canopy.
--Plants are able to actually touch the light and keep on growing. The only symptoms they've encountered is a slight lightening of the leaves when they grow within 6".
--There's no way my light could be defective.
--The problem could be some weird plant genetics.
--My dealer (Gotham) is usually pretty good about swapping the 240W for the 180W if that's what I really want (he recommended against the swap).
--I should keep trying various combinations until I figured it out. Once I found the solution to the problem, I'd really like the 240W UV. It's their best selling light by far, and it has completed thousands and thousands of successful grows.

After I hung up, I was all set to call Gotham and make the swap, but my mind started chewing on bits and pieces of the conversation. To make a long story short, after days of research and much trial and error (involving the sacrifice of 4 prime clones), I finally zeroed in on iron deficiency as the likely culprit. The exclusivity to new growth only was the tip-off symptom. Once I started adding chelated iron to my nutes, the symptoms began abating, and with one plant, the symptoms have disappeared altogether. The two photos below show a branch of this plant merrily growing within 6" of the light. The burned tips you see is left-over damage from earlier severe iron deficiency. Notice the slight lightening of the leaves in the foreground. I gather this is the real Blackstar light bleaching. Incidentally, those leaves are still growing quite robustly.

Attachment 283525Attachment 283526

So what in the heck is going on here?

After piecing together all my observations and all the results of my experiments, here's my working theory (it's not set in stone so if you have a better explanation I'm all ears). These iron deficiencies appear to be directly related to growth rates. I'm using SensiGrow and SensiBloom which have 0.12% and 0.13% iron respectively. With the growth rates of most all lights out there, this amount of iron is adequate. The 240W Blackstar, however, is so efficient at hitting plants at their chlorophyll-producing wavelengths, that all available iron is quickly drawn into growth, and the plant is unable to suck up enough new iron to prevent deficiency. The insidious aspect of this problem is it takes only a tiny and brief shortage of iron in the growing tips to effectively shut down all growth, and if left untreated, the shutdown will eventually kill the plant (I found this out the hard way on 3 fantastic plants). Making matters worse, recovery is slooow and growth rates never seem to return to their former glory. Although I've never heard of too-fast growth rates causing deficiencies, I have personally experienced too-slow growth rates causing toxicities, so it's not beyond the stretch of plausibility.

Thus, my end goal in all this is to come up with some method of preventing 240W Blackstar "iron shock" in the first place. Right now I'm experimenting with adding iron well before switching lights, and although the results of my experiments are a ways off, it's looking like if this approach works at all it will take between 2% and 5% added iron.

If any of you know of a proven method for preventing Blackstar iron shock, I'd greatly appreciate hearing about it in a post to this thread. If I come up with something, I'll do the same. Thanks in advance. Hataman.

[Cyclonite]

So what did u use? I could try upping the calmag plus dosage

[Hataman]

So what did u use? I could try upping the calmag plus dosage

I'm using Liquinox Iron & Zinc that I bought at a local nursery. It's 0.2% Iron and 0.2% Zinc. I'm up to 4 oz of Liquinox /gal of diluted nutes so FE is now approx. 1.72% of raw concentrated nutes. I've been prefeeding this extra iron to some clones in my 180W Blackstar veg box, and will transfer them to the 240W Blackstar bloom box in a day or two--keeping my fingers crossed. Also, I just bought some Bonide Liquid Iron Complex which is 5% FE plus a bunch of other micro nutrients. I'll try this if the current Liquinox dosages fail to prevent the problem.

As for the calmag plus, thanks for the offer to help, but none of the symptoms I've experienced look at all like either calcium or magnesium deficiencies. Plus, I originally thought this was a sulfur deficiency so I tried Epsom salt (magnesium sulfate) with no joy. This leaves me about 99% certain this is not a magnesium or sulfur issue, and 96% certain it is not a calcium issue.

On the other hand, all the symptoms I've experienced perfectly fit the description and photos of iron deficiency, and adding the Liquinox Iron is definitely improving things. This has me 99.5% convinced this is an FE deficiency. My remaining questions are primarily how, when, and how much iron to apply. Also, perhaps vegging with a different light setup might solve the problem. Dunno. Weâ??ll see.

[Cyclonite]

I was thinking along the lines of LEDs seem to make the plants need more cal-mag. Also cal-mag has iron in it as well so it could take care of all the issues in the right dose. It also has many other micro nutes the plants need

[redleb]

Thanks for your great work Hataman, Iâ??m going nowhere with thisâ?¦ Your ideas seem right, and symptoms are just what I have.. When it first happened I did think I had a pH problem causing Iron deficiency, but by the time I sorted it the damage was done and they never recovered.

Since I have been extra careful with pH & feeding, and the plants look really great until they get under the flower lights. Then they seem to have a strong burst of growth in the first week and the top leaves start to yellow by 10 days. Iâ??m now trying both flower & veg lights together, and only feeding pH adjusted seaweed.

The latest plant has been under flower for 10 days now and after reading your post I have just given it a shot of Iron (Sequestrene), it shouldnâ??t do any damageâ?¦ Iâ??ll let you know..

[HipsterDoofus]

This appears to be a sulfur deficiency.

Four of my eight plants looked exactly like this picture. And I recently switched to a new Blackstar 240W uv led. So if it was light bleaching shouldn't all the plants have been affected? Especially if they are taller than the affected plants?

I tried raising the lights. I tried the epsom salts and foliar feeding. Nothing. Started getting worse. In desperation I fed with Miracle Gro (yikes!) and the yellowing stopped. New growth is coming in fully green! Hooray!

I am growing a lowryder mix in forest farm ocean forest soil. I am using 1.3 gallon plastic pots in a 24 x 24 x 60 tent. Two of the eight plants are lowryder2. One shows the yellowing heavily, the other barely so.

Attachment 283562

[redleb]

My latest thinking is that it might be the shock of moving from 18 to 12 hrs and from veg to flower lights at the same time, stressing the plants. They do grow very well initially, but then seem to overstretch themselves and decline.

In my new trial I was going to give a plant 2 weeks of 12 hrs under the veg lights and then move them to flower lights, but things changed and I only managed 1 week, however the buds are as good (better) than original plants that have been under the flowering led for 3 weeks longer! It also did seem a good idea because it evens out the time requirement on both lights.

Unfortunately, I have been changing other things at the same time (just want to get it right!) so no real proof, but may well be worth bearing in mind.

Not sure whether the shot of iron did much good… maybe too late.. but my soil mix was enriched with iron to start with.

[Hataman]

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