Leaves Yellow Faster Under LED's

BigBudsBunny said:
i just looked at calmag-technaflora it's 2-0-0 so gonna give em some next feeding - can't hurt, gave em a little extra N last feeding which I don't like doing in flower. Just surprised they doing that under LED. Had no issues under HPS. We'll see what's up with LED's over the next month so I can compare it to an HPS grow. Ya know what they say....Adjust and Conquer!
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I've only grown with LED. I'm currently experimenting with hydro and forcing over into flower from veg. I have a few that have been yellowing and I think I have found the answers. Thank you for asking. I'm assume mine is a mixture with being stressed and the lights. I'm on well water myself and it's been awesome for veg.
 
BigBudsBunny said:
exactly the ratio i have been using for years 3g,2m,1b - veg, 2-2-2 transition 1,2,3 flower never had a problem under MH/HPS. just seems to be happening at a faster rate under LED's
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that's not the 3-2-1 i was referring to. that is good though lol.
 
Dustin84 said:
I've only grown with LED. I'm currently experimenting with hydro and forcing over into flower from veg. I have a few that have been yellowing and I think I have found the answers. Thank you for asking. I'm assume mine is a mixture with being stressed and the lights. I'm on well water myself and it's been awesome for veg.
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You might be right - IDk, I think the lack of red spectrum compared to HPS might be the issue or the increased blues spectrum on LED might be the issue. The only thing thaat changes was the lighting spectrum - so I might have to adjust for that or just go back to flowering under HPS. I'd rather have the flower than the savings due to LED efficiencies.

We'll see - less than 4 week to go to determine outcome and compare against my HID grows.
 
BigBudsBunny said:
Ok....lol....Spill the beans....! Always eager to learn more
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no worries lol. it's just the number of days between feeding intervals/watering in a hempy. it's pretty simple frankly.

standard hempy 3-2-1 feeding schedule.

seedling to mid veg - feed every 3rd day
mid veg to early flower - feed every 2nd day
mid flower to chop - feed every day

bonus info : on salt based bottle nutes run a f/f/w. on MC and most organic based bottle nutes run f/f/f. adding h2o2 in flower helps smooth things out.
 
bluter said:
no worries lol. it's just the number of days between feeding intervals/watering in a hempy. it's pretty simple frankly.

standard hempy 3-2-1 feeding schedule.

seedling to mid veg - feed every 3rd day
mid veg to early flower - feed every 2nd day
mid flower to chop - feed every day

bonus info : on salt based bottle nutes run a f/f/w. on MC and most organic based bottle nutes run f/f/f. adding h2o2 in flower helps smooth things out.
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hmmm...interesting. I've always watered/fed (about 10 years) when the pot was light. that's what i liked about it....lol
 
BigBudsBunny said:
hmmm...interesting. I've always watered/fed (about 10 years) when the pot was light. that's what i liked about it....lol
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by the time you are in early veg the pot should be dry by the days on the 3-2-1 schedule and you'd be following it anyway. if the plants don't use it all it's best to stick to the schedule as it smooths out any ph issues that can rear up.

hempy is one of the few things that can be fed on a calendar basis. near every other media is different. coco is somewhat similar.
 
BigBudsBunny said:
hmmm...interesting. I've always watered/fed (about 10 years) when the pot was light. that's what i liked about it....lol
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I never heard of that feed schedule. Again, my pots are made up of 3 parts perlite and 1 part vermiculite which might make a difference as the vermiculite holds the feed for a few days.

I guess I use a modified version, or maybe it's called something else, I tried various versions when starting out and just called em hempys. I typically feed about every 3-4 days thru flower/Established Veg cycles. When the bucket is light I feed - never had a problem and never had yellowing until very late in flowering under HPS UNTIL I switched to LED (which is ok, I know it's a trial and error thing until dialed in). When harvesting under HPS - buckets chock full of white to very light tannish roots. The last grow had 52" plants in 2 gal buckets (1st grow in years...ugh forgot how much they stretched and let em get to big). The plants under LED are a lot smaller - about 24" and started yellowing at week 5 (same strain as just harvested). Only change is lighting system. So it is using N faster than under HPS for some reason. To correct/adjust leads me to consider 3 options - 1st - do nothing (plants will finish no prob - 3 weeks left); 2nd feed more often - which concerns me about having wet buckets (root rot problems); 3rd increase nutrients at feeding times - which could lead to burn as the strain I grow (about 8 years now) never exceeded 600ppms for feedings before tip burn under hps - was a light feeder. My Veg plants are also showing signs of yellowing at the most bottom of leaves under LED - never had any issues under MH no matter how log I kept them. So have to figure it out is all. As I said prior, I'd rather have no problems and use less efficient lights with proven results than save some $ and have issues. Time will tell If I'm happy with LED when I harvest this batch. Did I mention I don't like issues!!! lol We will overcome!
 
BigBudsBunny said:
I've noticed that my plants are yellowing at a faster rate under LED as opposed to HPS despite being fed as usual. I've only been flowering under LED's for - this is week 6 of 10. Anyone else notice this when switching?

BBB
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Thats the main reason I don't use Led's on their own when flowering and always place an hps bulb next to them.
I have tried (a lot !) to veg and flower with just led's on their own but I always run into this problem of yellowing once I flip them into flowering. Led's are brilliant for vegging but when it comes to flowering boom !, around 2 to 3 weeks into flower the fan leaves begin yellowing and drying up and once the process starts there doesn't seem to be much you can do about it no matter what you try 🤔 eventually I just got fed up wasting time and money only to watch my plants slowly dry up so I just stick to my mh/hps combo now, at least I know where I am with those, guess I'm just old school 🤨.
I see lots of fantastic grows on this forum from people using led's and I have to wonder how the hell do they do it ? Beats me.

Day 50 day 21 of flower D.jpg

Day 50 day 21 of flower D.jpg




Above is an example of what I mean. I was using a quantum board for this grow and everything went swimmingly well during veg, you can see how bushy and healthy they look in the photo but 3 weeks after flipping them the problems began, leaves began crisping up and yellowing, if you look closely you can already see them yellowing. I tried everything from calmag, etc. but nothing helped and I just watched helplessly as they slowly withered. No more led's for me, I'm done.
 
aphrodisia said:
Those are 480 actual watts quantum boards with ir and no, they weren't light starved as you can tell from how bushy and squat they were before the flip
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Yeah but during flowering.. as you say the problems begin after stretch.. either they're too much if you're crisping & yellowing up leaves? Or if you keep it that high up they maybe getting too little, but sounds like it's powerful so that might not be the case.

There's also 4 UV in there? and how many IRs? are the two red lines in the middle all IR or reds? as if that's like 30 of them per board that might be excessive for such a surface area? and 480w is strong so you might be cooking them?
As that fade around the edges in a spear shape on that leaf.. I'm thinking light stress.
 
never really had an issue with led ... 600w cob led


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i don't run ir or anything but it's only a 3000k and 3500k mix.
 
aphrodisia said:
Those are 480 actual watts quantum boards with ir and no, they weren't light starved as you can tell from how bushy and squat they were before the flip
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The plants are short and compact which is a sign that, at some point, they got good light and/or that they received a lot of blue photons.

What are you using to measure your light output?

Just by eyeball, I'd say that the hang height has got to be at least 36". Even a 1k watt LED doesn't put out a lot of light at 36".


Re. yellowing and LED's - it's not an issue of the lights. There are lots of LED's in use for all sorts of agriculture all around the globe. If you're running into issues, you might post some photos, nute info, light (model, hang height, dimmer setting, and schedule) nutrients, watering practices, etc. so that folks can help diagnose the issue. It's frustrating to have a grow go sideways but there's lots of help here.
 
Fenderbender said:
Yeah but during flowering.. as you say the problems begin after stretch.. either they're too much if you're crisping & yellowing up leaves? Or if you keep it that high up they maybe getting too little, but sounds like it's powerful so that might not be the case.

There's also 4 UV in there? and how many IRs? are the two red lines in the middle all IR or reds? as if that's like 30 of them per board that might be excessive for such a surface area? and 480w is strong so you might be cooking them?
As that fade around the edges in a spear shape on that leaf.. I'm thinking light stress.
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Thats a Kingbrite Lmh301 quantum board and I didn't even have it turned up fully only at about half, I don't have all the specs to hand at the moment but it had deep red and also I think uv.
 
Delps8 said:
Re. yellowing and LED's - it's not an issue of the lights. There are lots of LED's in use for all sorts of agriculture all around the globe. If you're running into issues, you might post some photos, nute info, light (model, hang height, dimmer setting, and schedule) nutrients, watering practices, etc. so that folks can help diagnose the issue. It's frustrating to have a grow go sideways but there's lots of help here.
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hmmm not sure I think incorrect use or spectrum could definitely lead to yellow & crispy leaves. Too much or too little.

And I also think REDS are tricky to get right, I have a 100w of Philips 660nm somewhere in like 4 25w bars.. and well I can make a nice healthy plant be totally slumped over on the floor with it. I had it on a timer but that timer malfunctioned keeping the light on, after a couple of hours all the plants were weak and on the ground.

The Kingbrite seems to be 496 pcs Samsung LM301H + 64 pcs Epistar 660 nm + 8 pcs IR + 8 pcs UV.
And they seem pretty old school leds as they're just put on there in rows.. 240w per and two boards close together, I think that thing is hot spot central, most now have some mathematical placement so the centre isn't too hot and the sides get more reach..
I think with all the stuff in there this could be a tricky spectrum & flux to get used to to grow, or it could be just plain bad. As most stopped doing that quite quickly putting all the different chips on 1 board, because they burn out and there's no control, to really make use of the IR & UV you kinda want to be able to control the timing & intensity.
 
Fenderbender said:
hmmm not sure I think incorrect use or spectrum could definitely lead to yellow & crispy leaves. Too much or too little.

And I also think REDS are tricky to get right, I have a 100w of Philips 660nm somewhere in like 4 25w bars.. and well I can make a nice healthy plant be totally slumped over on the floor with it. I had it on a timer but that timer malfunctioned keeping the light on, after a couple of hours all the plants were weak and on the ground.

The Kingbrite seems to be 496 pcs Samsung LM301H + 64 pcs Epistar 660 nm + 8 pcs IR + 8 pcs UV.
And they seem pretty old school leds as they're just put on there in rows.. 240w per and two boards close together, I think that thing is hot spot central, most now have some mathematical placement so the centre isn't too hot and the sides get more reach..
I think with all the stuff in there this could be a tricky spectrum & flux to get used to to grow, or it could be just plain bad. As most stopped doing that quite quickly putting all the different chips on 1 board, because they burn out and there's no control, to really make use of the IR & UV you kinda want to be able to control the timing & intensity.
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"incorrect use" - it is possible to damage plants using an LED but it's not easy. If a grower ends up with yellow and crispy leaves as a result of using an LED, they've been grossly negligent. LED's do not put out much heat so to actually cause tissue death takes days of disregarding the grow.

"spectrum" - Sure, someone could design a light that would damage leaf tissue but the market for that would be pretty limited. "Deathray 400" probably isn't going to be a big seller. But there's nothing in a "standard" LED spectrum that would harm a plant unless the grower is grossly negligent.

Kingbrite - that's the cheap lights on Amazon? I haven't looked at them in some time and, from what I do know about them, they're not a light I would recommend because the are quality lights that are in a similar price range.
 
aphrodisia said:
Thats a Kingbrite Lmh301 quantum board and I didn't even have it turned up fully only at about half, I don't have all the specs to hand at the moment but it had deep red and also I think uv.
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You're not giving your plants very much light. If the photo that you posted is the actual grow tent, it's dark in there.

Here's a picture of my current grow. Compare the brightness in the tent in this photo to the one you posted.

I'd love to get the specs on your light and your set up - the actual board and the measured hang height - because, based on what you've posted (the info about the board and the picture of a dark grow tent) it's a tribute to cannabis that it will grow so well with so little light.


1728744437669.jpeg
 
Delps8 said:
Kingbrite - that's the cheap lights on Amazon? I haven't looked at them in some time and, from what I do know about them, they're not a light I would recommend because the are quality lights that are in a similar price range.
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i'm leaning toward this being the issue more than anything


aphrodisia said:
Thats a Kingbrite Lmh301 quantum board and I didn't even have it turned up fully only at about half, I don't have all the specs to hand at the moment but it had deep red and also I think uv.
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as noted it's a kitten brand. i would not count on the components being legit. ali baba is mostly known for fakes and knockoffs. i would have to seriously check that board to determine whether or not it was fugazi.

every fake claims to use lm's. and that's not even taking into account the drivers and other components.
 
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