Cupping + spotting

crimsonecho

Well-Known Member
Really bro? Dudes PPFD is less than 1000 ! and you're gonna call light stress? That's less than sunlight by far?

and have you ever tried giving plants way more light than recommended and then giving them way more nutes than recommended to compensate and test this theory. Doubt it.
well i’m gonna say what i see so dude can dim his lights and see if it works out for him and maybe after a week he can turn it up to 80% and then to 90% a week after that and then to 100% if everything goes well and during that process he can adjust his feeds and plants can get comfortable with the lights no need to stress them
 

I'm negan

Active Member
It would be difficult to throw that many umols at anything without causing heat damage first. But maybe not impossible. The point is, it is very difficult to give a plant too much light and probably blamed way more often than it should be. That's such a common theme around here and every forum. It's either too much light or not enough cal-mag.
well i’m gonna say what i see so dude can dim his lights and see if it works out for him and maybe after a week he can turn it up to 80% and then to 90% a week after that and then to 100% if everything goes well and during that process he can adjust his feeds and plants can get comfortable with the lights no need to stress them
Ok bro fair enough, but just once maybe try it as an experiment.... Next time you really have the urge to diagnose light stress, Increase your nutes. Just try it and you may be shocked.
 

SNEAKYp

Well-Known Member
It would be difficult to throw that many umols at anything without causing heat damage first. But maybe not impossible. The point is, it is very difficult to give a plant too much light and probably blamed way more often than it should be. That's such a common theme around here and every forum. It's either too much light or not enough cal-mag. Dude suggesting too much light when OP said he's got 500-1000 PPFD is a joke.
I totally agree with you within the 500-1000 PPFD range is not going to be overkill. In flower that’s underpowered. 1200-1800 is where I find the sweet spot. 2000+ and one missed watering then you are fucked.
 

crimsonecho

Well-Known Member
Ok bro fair enough, but just once maybe try it as an experiment.... Next time you really have the urge to diagnose light stress, Increase your nutes. Just try it and you may be shocked.
if they’re stressed to begin with throwing more nutrients on top of the stress will not solve the issue but compound it imo however i also don’t think 750umols is an overkill (if thats the actual median op sees) but most plants need acclimatisation as indoor stock thrown under the summer sun will burn first then gonna grow out of it (the uv is not the only culprit there) so if the op would first dim the lights a bit and it works he can then gradually turn it up and this way he doesnt create unneccessary stress for his plants and he can adjust feed etc and stop again if same symptoms appear. easy.
 
if they’re stressed to begin with throwing more nutrients on top of the stress will not solve the issue but compound it imo however i also don’t think 750umols is an overkill (if thats the actual median op sees) but most plants need acclimatisation as indoor stock thrown under the summer sun will burn first then gonna grow out of it (the uv is not the only culprit there) so if the op would first dim the lights a bit and it works he can then gradually turn it up and this way he doesnt create unneccessary stress for his plants and he can adjust feed etc and stop again if same symptoms appear. easy.
My apogee meter reads 1020 umols at the absolute highest part of my canopy, with most of it sitting between 600-800 and the corners dipping to 500.

My runoff PH after flushing is sitting at 5.0, which is a decrease since earlier. The top of my soil is at 6.8ph when I tested it in a 1 to 1 mix with RO water.

I typically grow in hydro but decided to give soil a try. I have no idea wtf is going on in the root zone or why I'm showing some deficiencies. I don't know if it's a PH induced lockout or what.

I've also basically drowned the plants over the last 5-6 hours but they are still praying hard.

Oh, and this is week 3 of flower. I should have said that before. Strain is Shiskaberry by Barney's Farm.
 

I'm negan

Active Member
My apogee meter reads 1020 umols at the absolute highest part of my canopy, with most of it sitting between 600-800 and the corners dipping to 500.

My runoff PH after flushing is sitting at 5.0, which is a decrease since earlier. The top of my soil is at 6.8ph when I tested it in a 1 to 1 mix with RO water.

I typically grow in hydro but decided to give soil a try. I have no idea wtf is going on in the root zone or why I'm showing some deficiencies. I don't know if it's a PH induced lockout or what.

I've also basically drowned the plants over the last 5-6 hours but they are still praying hard.

Oh, and this is week 3 of flower. I should have said that before. Strain is Shiskaberry by Barney's Farm.
Bro, fuck what dude is saying. Your light is fine maybe even a little too low... Is your fan on a switch or timer? I know you said your RH is 50% but have you calibrated your hygrometer? Doubt it, who does all that right? Those meters can be very inaccurate. i really think you have both a humidity problem and a nutrient deficiency... Not calcium because it's only in the older growth. Looks like low Nitrogen and low humidity. add a humidifier and keep your fan off a little more often put it on a thermostat if not already. Like i said i had the same problem in a 4x4 and humidifier solved it.
 

Samsung Kawasaki

Active Member
The cupping of the leaves like that is usually heat stress related, you probably just need to increase your airflow a bit more. Also looks like some rust spots which is usually a sign of calcium deficiency, since your feeding full strength cal mag its likely a lockout. Get your pH above 6.2 and your plant will be able to absorb the calcium available.
 

bam0813

Well-Known Member
So I'm not allowed to have an opinion? I've been into cannabis culture for 20+ years. I've seen a lot worst starts to a grow. Please critique my 3 week old plants that started as seedlings under full blast LED light 18 inches away and thrived. How do they look honestly?
Of course just dont state opinion as fact. 20+ yrs at 33 ....but still wondering if you got ripped on seeds and saying light stress is a myth lol
 

bam0813

Well-Known Member
Bro, fuck what dude is saying. Your light is fine maybe even a little too low...

But that shits a myth
 

crimsonecho

Well-Known Member
My apogee meter reads 1020 umols at the absolute highest part of my canopy, with most of it sitting between 600-800 and the corners dipping to 500.

My runoff PH after flushing is sitting at 5.0, which is a decrease since earlier. The top of my soil is at 6.8ph when I tested it in a 1 to 1 mix with RO water.

I typically grow in hydro but decided to give soil a try. I have no idea wtf is going on in the root zone or why I'm showing some deficiencies. I don't know if it's a PH induced lockout or what.

I've also basically drowned the plants over the last 5-6 hours but they are still praying hard.

Oh, and this is week 3 of flower. I should have said that before. Strain is Shiskaberry by Barney's Farm.
fuck what i’m saying but your led fixture provides ir and uv so dim them and see if that helps and if it does you can turn it up weekly, give plants a chance to acclimatise and catch up with the intense light is my suggestion. your call.
 

I'm negan

Active Member
Bro, fuck what dude is saying. Your light is fine maybe even a little too low...

But that shits a myth
Complete Myth. But understandably conflated because light and heat go hand in hand. Can you please use your bro science to explain to my simple mind what light does on a molecular level to cause physical damage to any object aside from heat? I'd be very interested in your answer.
 
fuck what i’m saying but your led fixture provides ir and uv so dim them and see if that helps and if it does you can turn it up weekly, give plants a chance to acclimatise and catch up with the intense light is my suggestion. your call.
They had 5 weeks of gradual increase to this level of light before I flipped to flower.

Bro, fuck what dude is saying. Your light is fine maybe even a little too low... Is your fan on a switch or timer? I know you said your RH is 50% but have you calibrated your hygrometer? Doubt it, who does all that right? Those meters can be very inaccurate. i really think you have both a humidity problem and a nutrient deficiency... Not calcium because it's only in the older growth. Looks like low Nitrogen and low humidity. add a humidifier and keep your fan off a little more often put it on a thermostat if not already. Like i said i had the same problem in a 4x4 and humidifier solved it.
My fan is on max all the time. Where I live the ambient humidity outside is about 60-80% this time of year. The hygrometer outside the tent measures 57% inside the tent measures about 50%. No idea how to calibrate them

I'm going to see if I can do anything about the root zone PH and report back here in a day or two.

Thanks for your help guys, really appreciate all the input.
 

bam0813

Well-Known Member
Ok let’s go to first grade. When you go to the beach do you get sunburned cause the temp is 95?
 

crimsonecho

Well-Known Member
Complete Myth. But understandably conflated because light and heat go hand in hand. Can you please use your bro science to explain to my simple mind what light does on a molecular level to cause physical damage to any object aside from heat? I'd be very interested in your answer.
E42D645D-6A53-4070-A297-50B7CD863809.jpeg

They had 5 weeks of gradual increase to this level of light before I flipped to flower.



My fan is on max all the time. Where I live the ambient humidity outside is about 60-80% this time of year. The hygrometer outside the tent measures 57% inside the tent measures about 50%. No idea how to calibrate them

I'm going to see if I can do anything about the root zone PH and report back here in a day or two.

Thanks for your help guys, really appreciate all the input.
they’re your plants bro
 

bk78

Well-Known Member
Complete Myth. But understandably conflated because light and heat go hand in hand. Can you please use your bro science to explain to my simple mind what light does on a molecular level to cause physical damage to any object aside from heat? I'd be very interested in your answer.
Welcome to the forum :bigjoint:
 

bk78

Well-Known Member
Light stress is a myth. You can have too much heat but not to much light. I know this isn't a popular opinion but the data backs it up. Under optimal conditions a cannabis plant can handle more light than you can possibly throw at it while maintaining temps. The real problem is people don't give them optimal conditions then blame the light intensity.
Can you post said data please?
 
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