What is happening to my plants?

[Fourpey]

My 2 plants were getting 250 ppfd and 3 micro/4.5 bloom/1 calmag up until yesterday. Since they are slipping out of their seedling phase I switched feed strength to 6/9/1 and cranked light intensity to 400 ish ppfd. I fed them this morning and the top leaves were a normal unified green color. I came home to them looking like this. Can anybody tell what the problem is. The feeds have been pH'd to 5.8-6.2 since the beginning but this last one was at 5.5, is that small pH fluctuation enough to be causing this? First grow in coco perlite grow btw.

Thanks for the help

 

[Fourpey]

the pH was 5.6 after rechecking.

 

[ArtfulCodger]

My guess is that it's too much light, based on the yellowing between the veins.

 

[Fourpey]

My guess is that it's too much light, based on the yellowing between the veins.

Ok so I'll lower to 60% and see. I am worried it was because of the nutrients

 

[Newty]

What light brand/model are you using?
How high above plant?
60% seems like a lot to me but it depends on what light and height.
My plants in veg see only 30%-40% power at 24"-30" high all through veg and into the first couple weeks of flower, then I start raising intensity.

Are you using Flora Series Nutrients? If so why just Micro and Bloom but no Grow?

 

[Fourpey]

What light brand/model are you using?
How high above plant?
60% seems like a lot to me but it depends on what light and height.
My plants in veg see only 30%-40% power at 24"-30" high all through veg and into the first couple weeks of flower, then I start raising intensity.

Are you using Flora Series Nutrients? If so why just Micro and Bloom but no Grow?

2'x3'x6' tent
2 AC Infinity IONBOARD S22 100W (good for 2’x2’)
1-1/2 foot
My plants were at 40% intensity at 1-1/2 foot since they germinated, and just now I cranked to 80%.
All I measured for ppfd was with photone app and I doubt its very reliable.

I am using the flora series only Micro, Bloom and CalMag. Doing H3ad's formula

 

[hardgrow]

I made same mistake with light intensity,
have 2 240w led panels 301h . once i go more then 50-60% depending on the rest of environment
starting to get burns all over. 18-24" distance.
now im flowering with 40-50% each , it sometimes to much as well.
leds also love cal mag in coco more then usual , i use 0 nitrogen cal mag can use it till end of flowering

 

[Thatoneguyyouknow_]

Ive never been able to light burn a plant with an LED panel. The geometry of the light overlapping kinda fights against you there. After agetting within about 12" from most panels, you are actually losing light intensity because its coming from hundreds of individual overlapping sources that are not at a single point. Go too close and they are not evenly overlapping. Ive had some nutrient deficiency/processing issues with LED's being close that i havent had with other lights, but that isn't at all because there's too much light. Just seems to be something a lot of plants do under light that wasn't created by ionized plasma along side the plants not actually getting the full available spectrum of mixed light because the panels are too close and the chips arent overlapping properly at that point.


It doesn't exactly work like an HPS bulb, where the closer you are, the more light you have. There is a thin red line in there with every LED panel.


That being said ive vegged and flowered plants within 12-14" of 480w LED panels at 100% and havent had issues with most of them. Generally when i flip to flower, ill back the panel off to a couple feet, and let the plants stretch into the light themselves. I usually dont back it off until tips get within like 6 inches of the panel. Ill have some yellowing upper fan leaves, but i end up with a bigger bulk to the main, dense areas of the canopy that way.


Although im probably going to migrate back to T5/HPS this summer . I dont like having to partially etiolate plants when young just because they aren't fans of the kind of incredibly unnatural feeling (even to my own eyes) synthetic light that LED's produce. I actually switched to LED at the same time i transitioned to DWC, so i chalked my nutrient processing issues up to the DWC transition, even though only certain plants had the issues. and i only had 8-10 runs with that setup before i retired from growing for several years. Now that im back growing, in soil, under LED panels, i have definitely formed a different opinion on LED's then i used to have lol.



5.5-5.6 should be fine in coco/perlite for a watering, just dont leave it there through multiple waterings or youll start to develop calcium/magnesium lockouts. I always ran in the 5.8-6.4 range in coco for most plants. closer to that 6.4 range in flower usually. closer to the 5.8-6 area in veg.

 

[Newty]

Ive never been able to light burn a plant with an LED panel. The geometry of the light overlapping kinda fights against you there.

Maybe I'm misunderstanding what you're saying but there's weekly, sometimes daily, posts of people burning the plants with LEDs even as far away as 18"-24". Whether it be a board, panel, bar, etc

While I was dialing in my Spider Farmer SE4500 for the first time, I started seeing burning at 50% at 20", moved to 24" at 40% and issue solved.

 

[Beachbumm]

Maybe I'm misunderstanding what you're saying but there's weekly, sometimes daily, posts of people burning the plants with LEDs even as far away as 18"-24".

While I was dialing in my Spider Farmer SE4500 for the first time, I started seeing burning at 50% at 20", moved to 24" at 40% and issue solved.

There's posts of people telling them it's light burn, doesn't mean it actually is light burn.

 

[Newty]

There's posts of people telling them it's light burn, doesn't mean it actually is light burn.

So when they lower intensity and/or raise the light and the issue is corrected, what does that mean?
If I can learn something, I'm all for it.

 

[Thatoneguyyouknow_]

So when they lower intensity and/or raise the light and the issue is corrected, what does that mean?
If I can learn something, I'm all for it.

could mean you might have a plant that doesnt like LED light. And if too close has difficulty processing and moving around certain nutrients. I have a half lan race sativa lineage and ive come to the conclusion that most of them hate most forms of LED light. That's not what light burn is though. Is similar, but Like i said ive never once managed to light burn a plant under LED's, or even begin to approach anything akin to bleaching of tissues. Def have with HID lighting though lol. Light burn, and tissue bleaching are things based in the total luminous flux of an environment. Has more to do with the luminous intensity which LED's arent actually super great at pulling off. They just have a much higher portion of their visible light tuned to the phosynthetically active range (PAR). You'll damage their chloroplasts and mitochondria, their ability to handle and process nutrients, before you light burn or bleach them under LED's.

Under HPS, you canlight burn and bleach buds, and so long as temps are managed, the material will sometimes even still continue to develop. The chlorophyl hasnt been destroyed in the case of light bleaching either, the plant just moved it elsewhere, where its better suited. It cant do anything with light that intense etc. The yellowing LED's cause when too close, seems to affect the plant's health a bit more then just some light burn or bleaching on the closest tips. At least in my experience now. It's seems a whole package of often inconsistent symptoms plant to plant.

My slowly forming conclusion seems to be that too much PAR, can be just as, if not even more destructive then too much light in general.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10106908/

There's a lot more reading where this comes from too. Thanks for the link @Stokes

 

[Beachbumm]

So when they lower intensity and/or raise the light and the issue is corrected, what does that mean?
If I can learn something, I'm all for it.

I didn't say there's no such thing as light burn, I said a lot of it isn't light burn.

Light burn seems to have become the new catch-all, even surpassing "Cal-mag"

 

[Newty]

could mean you might have a plant that doesnt like LED light. And if too close has difficulty processing and moving around certain nutrients. That's not what light burn is though. Like i said ive never once managed to light burn a plant under LED's, or even begin to approach anything akin to bleaching of tissues.

Well nutrients and light go hand in hand, they need to be balanced so correcting your light intensity or correcting your nutrients are both possible solutions to the same issue.

 

[Thatoneguyyouknow_]

Well nutrients and light go hand in hand, they need to be balanced so correcting your light intensity or correcting your nutrients are both possible solutions to the same issue.

if the light is causing nutrient processing difficulties, changing your nutrient solution wont fix much, if anything lol. May actually make your problems worse.

A change from 6.2 to 5.5 in coco would create, although very mild, a likely temporary calcium/magnesium lockout. If lights are LED when this happens, this problem will probably be amplified. Lotta variables at play, and its all just speculation when you arent the one with the plant in front of you keeping track of the variables lol.


Having your lights too close would creat some magnesium and nutrient processing issues with LED on its own though as well with some plants.

As your plant sits, id probably still just be watching and waiting until i had progressed symtoms to inform me a little more. I wouldn't call that a sick plant, not yet anyway. Trying to handle virgining problems too soon can actually bite you in the ass pretty good sometimes. Watching, observing, and learning now will help you greatly should you ever face the issue again. You'll actually know what the issue is, and what it was that resolved it.

 

[Fourpey]

if the light is causing nutrient processing difficulties, changing your nutrient solution wont fix much, if anything lol. May actually make your problems worse.

A change from 6.2 to 5.5 in coco would create, although very mild, a likely temporary calcium/magnesium lockout. If lights are LED when this happens, this problem will probably be amplified. Lotta variables at play, and its all just speculation when you arent the one with the plant in front of you keeping track of the variables lol.


Having your lights too close would creat some magnesium and nutrient processing issues with LED on its own though as well with some plants.

As your plant sits, id probably still just be watching and waiting until i had progressed symtoms to inform me a little more. I wouldn't call that a sick plant, not yet anyway. Trying to handle virgining problems too soon can actually bite you in the ass pretty good sometimes. Watching, observing, and learning now will help you greatly should you ever face the issue again. You'll actually know what the issue is, and what it was that resolved it.

Thats exactly what I did. I kept the same 6/9/1 feeding strength I had switched to but lowered the lights back down to 40% as they were and monitored the situation over the last 2 days. The plant has not slowed down growing. Here are pictures of it 2 days later following when I posted. The new growth seems normal and the rest of the plant has'nt worsened I think.

It really does look like a magnesium deficiency too. I'm going to let the new growth grow a little and if it looks the same light green striped I'll adjust the feed adding more calmag? The pH of the coco itself seems to be stuck at 6.5-7 since the beginning. I'm always feeding at around 5.8 and the runoff pH is 6.2-6.4.

Still not certain of anything since this is my first ever grow but my feeling is that doubling the light from 40% to 80% might have been too much for these 3 week old plants. Photone must be severely under reading the ppfd.

 

[Thatoneguyyouknow_]

i think you have a cal-mag lockout beginning to show its face. id definitely bring it back up a little next watering. But a plant lookin like this could be ovewatering too. Could be the light causing some funk. tbh im not sure


Can you take a pic with the entire plant squarely in view?



Down at 5.5 though, you've pretty much completely cutoff the cal mag. You dont want to stay there for long. You need to be that direction for some micronutrient availability. But calcium and magnesium becomes less bioavailable at those acidities. A small young plant growing quickly, will show a cal-mag lockout very quickly sometimes too. cal-mag lockout is really the same thing as cal-mag deficiency, just caused by an inability to absorb the nutrients from the soil, rather then a lack of their presence.

If you are using distilled or RO water. cal-mag lockout can happen even faster.

 

[Fourpey]

I'm using tap water that has a baseline ppm of 162. My feed has 6 ml of Micro, 9ml of bloom and 1 ml of calmag per gallon.
At first I mixed at 5.5, since I saw this change I corrected it to 5.8. My runoff ppm is 800ish with a pH of 6.2. The soil pH is indicating 7 on my meter. They have been getting roughly 1/4 gal of water once a day the last 3 or 4 feeds. When I'm nearly done pouring that the runoff starts at the bottom.

I'm confused lol, anyway here is the whole picture, both the same strain gdp.

 

[Newty]

if the light is causing nutrient processing difficulties, changing your nutrient solution wont fix much, if anything lol. May actually make your problems worse.

Exactly what I was getting at, that's why we recommend lower light intensity or raising the light.
Just because we call it light burn doesn't mean we are literally saying the LEDs are burning the plant, just another one of those terms used in the hobby.
Then there's also heat stress, which can be caused by any light.

 

[Grower1974]

It’s very difficult to actually “burn” plants with LED’s. Cannabis plants can’t get too much light. They only process what they can use. This is why they grow so much more happy/agressive outside in direct sunlight at 2000-2400ppfd.

I’ve bleached the very top of a few colas, but they were literally touching the LED bar at 108°F. 2” below that, the buds and leaves were still perfect. That distance, they were seeing betwen 1200-1400ppfd.

I veg all my plants at at least 550-650ppfd at 400W and 14-18” above the canopies.

Environment and nutrient processing is much more important.