I'm so lost, plants are sick

[Thatoneguyyouknow_]

Not to be a dick, im just kinda surpised here.

what kind of nasty lights are you guys using that burn plants at 450 ppfd? and 300 ppfd wont burn iceberg lettuce let alone cannabis.


Ive been growing nearly 20 years and never once seen that. If hes having a light related issue, its magnesium and calcium processing because hes using LED light, and if he popped it outside (after actually light burning from the immediate transition) it will recover. Or pop it under a t5 at 500 ppfd and it will too, prob without even burning.


Light burn down not spread evenly through foliage before killing the most affected tissue. It just doesnt.

If you back the light up enough with this being your problem, the plant will recover, LED's specifically are likely your problem, not too much light. This is a *constantly* misdiagnosed and misunderstood problem. But in that case, it's not light burn, see those long term university case studies on LED light im pretty sure i linked you before already.


Heres some good examples of light burn/ bleaching. They are not homogenous, plant-wide issues. They only effect the parts of the plant recieving too much light.


Take care to notice the only thing affecting the growth under that bleached flower is heat stress. Not light burn. That is what happens with too much light *if you are properly managing temps still*




Your new growth looks better then old too, deficiencies and nutrient issues effect older growth first, always. At least in my own experience, also ime Light issues effect the newest. and closest to the light first. for obvious reasons.

 

[Thatoneguyyouknow_]

Id bet money if you did nothing, and just kept going letting the issue progress, it would look more like this


A likely magnesium processing issue caused by LED light in general. This lineage handles extreme light better then most do. Just not LED light.


Thats not light burn, calling something that it isn't creates confusion for new growers. Yea its light related, isnt burn...

 

[Fourpey]

Id bet money if you did nothing, and just kept going letting the issue progress, it would look more like this


A likely magnesium processing issue caused by LED light in general. This lineage handles extreme light better then most do. Just not LED light.


Thats not light burn, calling something that it isn't creates confusion for new growers. Yea its light related, isnt burn...

So would just setting the LED at the top of my tent and leave it at 50% help?

 

[Thatoneguyyouknow_]

So would just setting the LED at the top of my tent and leave it at 50% help?

if thats the issue, yes, all im trying to do is communicate the difference between that problem, and light burn, so you can learn from your own observations without making a mistake. For example, if you ever transition a plant outside with this issue, you need to just suck it up, and expose the plant to intense light and deal with a plant that doesnt look its best, so it doesnt *actually* burn during the transition to outdoors where light is frankly, wtf intense sometimes.


Knowing the difference between the two seems to be the key for a smooth transition from LED to outdoors as well if you ever find yourself doing that (very common)



For more examples (im sorry i take myself to be a bad instructionalist/teacher honestly)


This is that same lineage i just pictured that doesnt like LEDS (i thought it didnt like DWC and actually took me a long time to figure this out personally)

, i cant find my par meter, but its 230, and i can tell you all three of these plants are seeing about 1600+ ppfd right now.



Anyhoo, first wo, standing proud in 93F weather at over 1600ppfd. Its probably the most sun loving lineage ive ever grown, but under LED has constant weird magnesium issues that are worse the closer it gets to thte light)

This is what all of my other plants look like right now, even with nicely moist root systems, still no burn though. Just a little heat stress.

 

[Thatoneguyyouknow_]

^the plants from that lineage have been able to grow within 1 foot of 1kw HPS light, and have bleached tips before showing light burn issues as well


Too close to an LED though, and it gets all kinda funky, isnt light burn though, technically, its localized magnesium deficiency. But also doesnt quite tit for tat express like usual mag deficiency, but its damn close.

That lineage is half columbian land race, it loves light, lots of light.

I mean not to be an ass hat, genuinely, but you guys calling that light burn should be taking notes right now. And doing research into this. It wont be nearly as obvious to growers of exclusively LED grown indoor cannabis. The misunderstanding is incredibly understandable too lol. I though tthis plant just didnt like DWC and it being affected by the closeness of the LED was confusing to me for a long time. I had just brought the plant (in that case, the specific clone as well as the land race pollen donor) over from 1kw HPS and light burn it never did. Basically ever, not under sunlight or HPS. I can pop the peaceblaster lineage seeds under full sun outside they do fine, i tested it this spring with one of them.


Im also not saying any one particular thing is your issue, im just saying that isnt light burn. You can grow iceberg lettuce under LED light that intense just fine. A plant that would literally die in a couple hours facing what my plants are this very moment.

 

[Fourpey]

if thats the issue, yes, all im trying to do is communicate the difference between that problem, and light burn, so you can learn from your own observations without making a mistake. For example, if you ever transition a plant outside with this issue, you need to just suck it up, and expose the plant to intense light and deal with a plant that doesnt look its best, so it doesnt *actually* burn during the transition to outdoors where light is frankly, wtf intense sometimes.


Knowing the difference between the two seems to be the key for a smooth transition from LED to outdoors as well if you ever find yourself doing that (very common)



For more examples (im sorry i take myself to be a bad instructionalist/teacher honestly)


This is that same lineage i just pictured that doesnt like LEDS (i thought it didnt like DWC and actually took me a long time to figure this out personally)

, i cant find my par meter, but its 230, and i can tell you all three of these plants are seeing about 1600+ ppfd right now.



Anyhoo, first wo, standing proud in 93F weather at over 1600ppfd. Its probably the most sun loving lineage ive ever grown, but under LED has constant weird magnesium issues that are worse the closer it gets to thte light)

View attachment 2192522
View attachment 2192523




This is what all of my other plants look like right now, even with nicely moist root systems, still no burn though. Just a little heat stress.
View attachment 2192521

Nice, so the LED would be causing mg imbalances, more like light stress than light burn. I put my 2 panels at the very top of the tent at 50% and photone reads 220ppfd atm. I'll leave it at that and come see if the plants seem like they want more light near the end of their day cycle. What would be signs of them needing more? Still praying near lights out?

Also the curling down tips of the leaves, what does that mean?

 

[Thatoneguyyouknow_]

Nice, so the LED would be causing mg imbalances, more like light stress than light burn. I put my 2 panels at the very top of the tent at 50% and photone reads 220ppfd atm. I'll leave it at that and come see if the plants seem like they want more light near the end of their day cycle. What would be signs of them needing more? Still praying near lights out?

Also the curling down tips of the leaves, what does that mean?

if your nodes start to become unsatsifyingly spaced apart, that is the beginnings of etiolation/stretching for light. anything under a few inches is generally fine indoors, you can even play with a balance of intensity and backing it off for different genetics to get more light through the plant without defoliating then upping the intensity slowly going into flower so you get more penetration. You can definitely play with light levels, just dont ever dramatically up the intensity all at once, wean if going up. Some plants will stretch a little if going down before they level out too. usually not a big deal.

Cannabis can take very intense and very low light before its physical health suffers to much compared to most plants, plants under low light will just get real lanky and spaced out.

 

[Thatoneguyyouknow_]

Sorry for double post, but another thing worth mentioning/nuancing, is that a plant suffering from light burn will not produce quality flower near the affected growth and the flower will burn too. Quite rapidly usually.


If you are dealing with that LED sensitivity, you can still take a plant all the way through to harvest of quality flower, your yeilds and terps will just be a pretty off. You'll still have good quality smokable flower even on the tips closest to the light. Not that you should ever do that on purpose, just worth mentioning. That issue can indeed meander on for a while slowly before becoming severe.


A part of me still thinks you just have a crappy batch of coco too. Happens ime, especially from compressed bricks.

 

[Fourpey]

Sorry for double post, but another thing worth mentioning/nuancing, is that a plant suffering from light burn will not produce quality flower near the affected growth and the flower will burn too.


If you are dealing with that LED sensitivity, you can still take a plant all the way through to harvest of quality flower, your yeilds and terps will just be a pretty off. You'll still have good quality smokable flower even on the tips closest to the light. Not that you should ever do that on purpose, just worth mentioning.

Sorry for double post, but another thing worth mentioning/nuancing, is that a plant suffering from light burn will not produce quality flower near the affected growth and the flower will burn too. Quite rapidly usually.


If you are dealing with that LED sensitivity, you can still take a plant all the way through to harvest of quality flower, your yeilds and terps will just be a pretty off. You'll still have good quality smokable flower even on the tips closest to the light. Not that you should ever do that on purpose, just worth mentioning. That issue can indeed meander on for a while slowly before becoming severe.


A part of me still thinks you just have a crappy batch of coco too. Happens ime, especially from compressed bricks.

I can't wrap my head around what it could be... the coco's quality, the pH of the coco, the LED's, the amount of nutes I'm feeding, the amount of water per feed I'm giving... And I can't start changing everything all at once because if it works, I won't know what actually did...

So I'll start with the lights and let it grow more and keep the same feed schedule. If it worsens I'll try something else I guess...

 

[Thatoneguyyouknow_]

I can't wrap my head around what it could be... the coco's quality, the pH of the coco, the LED's, the amount of nutes I'm feeding, the amount of water per feed I'm giving... And I can't start changing everything all at once because if it works, I won't know what actually did...

So I'll start with the lights and let it grow more and keep the same feed schedule. If it worsens I'll try something else I guess...

i had unhealthy plants regardless of PH, whihc was quite bouncy anyway, the very last time i used expanded coco bricks and is the entire reason i moved away from coco. I couldnt figure it out. This wasnt under LED lights it was under metal halide. I repotted to a mixed soil and brought the PH up and the issues went away. This was early 10 years ago though mind you. Fairly old memories. Since then ive reccomended bagged coco over bricks as i had a plant in bagged coco doing just fine at the time. Problem with bagged coco is price compared to compressed bricks. It costs a lot more to ship.

I ended up transitioning to DWC after went back to soils, because coco was just my first attempt to escape constant silica dust exposure with perlite and soils. I bet ill enjoy not being on dialysis when im 60 for it lol. Anyone who mixes large volumes of dry soil or works directly with perlite needs to wear an approved mask for silica exposure but nobody ever does/did myself included lol. Although these days, mixing dry soil and perlite, im wearing a damn good respirator lol. )


idk if thats your issue, i just have a past experience nagging me with some similarities.

 

[Fourpey]

i had unhealthy plants regardless of PH, whihc was quite bouncy anyway, the very last time i used expanded coco bricks and is the entire reason i moved away from coco. I couldnt figure it out. This wasnt under LED lights it was under metal halide. I repotted to a mixed soil and brought the PH up and the issues went away. This was early 10 years ago though mind you. Fairly old memories. Since then ive reccomended bagged coco over bricks as i had a plant in bagged coco doing just fine at the time. Problem with bagged coco is price compared to compressed bricks. It costs a lot more to ship.

I ended up transitioning to DWC after went back to soils, because coco was just my first attempt to escape constant silica dust exposure with perlite and soils. I bet ill enjoy not being on dialysis when im 60 for it lol. Anyone who mixes large volumes of dry soil or works directly with perlite needs to wear an approved mask for silica exposure but nobody ever does myself included lol. (yay for harm reduction)


idk if thats your issue, i just have a past experience nagging me with some similarities.

I'm just trying to save my first grow haha, learning a shit ton along the way.

 

[Thatoneguyyouknow_]

I'm just trying to save my first grow haha, learning a shit ton along the way.

if backing the light off isnt seeming to help, and neither does flushing and PH amending, yea at that point id consider repotting them, but that can stall your girlies out for a while before they take off again, def use that as your last available option. Im not sure if you can do or add anything to a container of coco to make it not behave like an inert hydro medium or not.

Your grow is far from being ruined, having issues early on is how you learn the most the quickest honestly.

Sometimes people have a couple solid grows soon as they start, in that case running into issues can seem apocalyptical. Def be glad you have em early on lol.

 

[Fourpey]

if backing the light off isnt seeming to help, and neither does flushing and PH amending, yea at that point id consider repotting them, but that can stall your girlies out for a while before they take off again, def use that as your last available option.

Cool, next time I'll be going with loose coco not bricks.
Can I flush with pH'd tap water? My tap ppm is 162

 

[Thatoneguyyouknow_]

Cool, next time I'll be going with loose coco not bricks.
Can I flush with pH'd tap water? My tap ppm is 162

i always did when at a house that had tap water. Really all thats uptakable in tap water is trace amounts of silica, calcium, and magnesium. Is enough to keep a plant from dying if its all you gave them, but not enough to actually feed a plant of any real size.

Here id be using ph'd RO water because i have terrible quality well water. Im sure many would recommend flushing with distilled or RO

 

[Fourpey]

i always did when at a house that had tap water. Really all thats uptakable in tap water is trace amounts of silica, calcium, and magnesium. Is enough to keep a plant from dying if its all you gave them, but not enough to actually feed a plant of any real size.

Here id be using ph'd RO water because i have terrible quality well water. Im sure many would recommend flushing with distilled or RO

i always did when at a house that had tap water. Really all thats uptakable in tap water is trace amounts of silica, calcium, and magnesium. Is enough to keep a plant from dying if its all you gave them, but not enough to actually feed a plant of any real size.

Here id be using ph'd RO water because i have terrible quality well water. Im sure many would recommend flushing with distilled or RO

Cool! Last question, when you flush do you flush until output ppm and pH is same as input? And do you feed with nutes right after or do you only feed the next time you wouldve fed them?

 

[Thatoneguyyouknow_]

Cool! Last question, when you flush do you flush until output ppm and pH is same as input? And do you feed with nutes right after or do you only feed the next time you wouldve fed them?

The way i flush, is ill put like 2-3 gallons of water at a certain PH through a 1 gallon pot and then check the last of the runoff. Yea ill go till runoff is more or less the same as input water.

You can feed a normal amount immediately after, the excess water will be pushed through the bottom and leave most the nutrient solution around the roots. It can work fine because either way your going to be left with the same volume of moisture around the roots with coco post flush. Fed or not. Theres no reason not to assuming total confidence your nutrient solution isnt the issue. Which i see no reason to suspect personally. I tend not to in soil, but prob would in coco.
Deficiency can manifest quite fast in coco. Even though it doesnt feel like it, you are technically growing hydroponically with straight coco. food is good lol.

 

[Fourpey]

The way i flush, is ill put like 2-3 gallons of water at a certain PH through a 1 gallon pot and then check the last of the runoff. Yea ill go till runoff is more or less the same as input water.

You can feed a normal amount immediately after, the excess water will be pushed through the bottom and leave most the nutrient solution around the roots. It can work fine because either way your going to be left with the same volume of moisture around the roots with coco post flush. Fed or not. Theres no reason not to assuming total confidence your nutrient solution isnt the issue. Which i see no reason to suspect personally. I tend not to in soil, but prob would in coco.
Deficiency can manifest quite fast in coco. Even though it doesnt feel like it, you are technically growing hydroponically with straight coco. food is good lol.

I went ahead just in case and gave them a good flush at 5.8 pH/185ppm until it came out 6.3 pH/220ppm. I saw ppm lower drastically from 1000 to 200 while flushing but the pH weirdly remained the same throughout. I will continue feeding them the 800ppm solution twice a day with the lights now further away from the plants and monitor the situation. Thank you so much for your help

 

[Thatoneguyyouknow_]

I went ahead just in case and gave them a good flush at 5.8 pH/185ppm until it came out 6.3 pH/220ppm. I saw ppm lower drastically from 1000 to 200 while flushing but the pH weirdly remained the same throughout. I will continue feeding them the 800ppm solution twice a day with the lights now further away from the plants and monitor the situation. Thank you so much for your help

Keep an eye on the PPM of the drainage then. If it was up over 1000 ppm at first flush then your probably feeding a little bit more then the plant wants to consume right now. Its probably leaving some feed behind as it consumes the water. Im not sure if id be feeding every watering or not if its 2x a day, i havent done coco in so long now i dont remember


I can say in DWC, where roots are permanently suspended in nutrient solution, i never go over 800ppm, usually more like 650. But dwc also has zero buffer and you dont ever go back and forth between nutrient solution and plane water unless you are cleaning the root systems off. If your feeding every watering id cut back the levels just a little bit. But im cross referencing this info against another grow method im more recently experienced with. Dont take my word for this bit of advice, def do research there.

 

[mobshit]

Nice, so the LED would be causing mg imbalances, more like light stress than light burn. I put my 2 panels at the very top of the tent at 50% and photone reads 220ppfd atm. I'll leave it at that and come see if the plants seem like they want more light near the end of their day cycle. What would be signs of them needing more? Still praying near lights out?

Also the curling down tips of the leaves, what does that mean?

your light being too close will cause cal mag issues