Possible nutrient burn, light burn or deficiency?

[Delps8]

looks like nute burn how far are your lights from the tops & what light strenth are you at PPFD DLI? what medium are you growing in?

I don't see any indication of excess light - tacoing or other photo avoidance.

I'll put a small wager on VPD being high (tip burn) and

[time passes - zooms in on temp and RH values]

That temp/RH gauge looks like one I saw in a thread last week.

80° and 40% = 1.9

Cannabis does well at 1.2-1.4 in flower. At 1.9, the plant is taking up and pumping lots of water because it's so hot and dry. Unless PPM is dropped, there's a lot of chemicals going into the plant that it can't process. That leads to tip burn and/or a nute imbalance.

I hit the same thing in my current grow switching to flower. I tried "Bloom" nutes (put a big dent in my bottle of pH Up) and, when I switched back to regular nutes at 640/500PPM, things did not go well. I had to drop to 540 and 470 before it stopped. Doing fine now at 390/500.

It's mpossible to say that the high VPD is the cause with this grow but this is a great example of VPD that is extremely high.

When you hear hoofbeats, think horses not zebras - the Amazon man would be dropping of a humidifier most tick if that was my grow.

 

[con]

I don't see any indication of excess light - tacoing or other photo avoidance.

I'll put a small wager on VPD being high (tip burn) and

[time passes - zooms in on temp and RH values]

That temp/RH gauge looks like one I saw in a thread last week.

80° and 40% = 1.9

Cannabis does well at 1.2-1.4 in flower. At 1.9, the plant is taking up and pumping lots of water because it's so hot and dry. Unless PPM is dropped, there's a lot of chemicals going into the plant that it can't process. That leads to tip burn and/or a nute imbalance.

I hit the same thing in my current grow switching to flower. I tried "Bloom" nutes (put a big dent in my bottle of pH Up) and, when I switched back to regular nutes at 640/500PPM, things did not go well. I had to drop to 540 and 470 before it stopped. Doing fine now at 390/500.

It's mpossible to say that the high VPD is the cause with this grow but this is a great example of VPD that is extremely high.

When you hear hoofbeats, think horses not zebras - the Amazon man would be dropping of a humidifier most tick if that was my grow.

nope no wager there Lol, great explanation there @Delps8

 

[Delps8]

nope no wager there Lol, great explanation there @Delps8

Thank you — I just hope it's right!

 

[KeyFinger]

Could be calcium, potassium or phosphorus if you ask me, but apparently there's more than just one issue. Perhaps indeed the nutes burn, I guess you can give them extra water for few days to wash away excessive then just give them a regular fertilizer?

 

[Lexstar]

Getting yellow/brown leaves and brown spotting on leaves, trying to fix it before it gets worse... Appreciate any help or advice, thanks in advance!

Def. nute burn.

 

[SMCelite36]

Def. nute burn.

I added the recommended 1 tbsp per gallon of Gaia Green 2-8-4 and 4 tbsp per gallon of worm castings, previous to that, i was adding both the 4-4-4 and 2-8-4, plus the worm castings until about 2 weeks into flower, at which point, I stopped adding the 4-4-4, then this started. It makes no sense that previous to them flowering, I was giving them more nutes, then when I stopped giving them the 4-4-4 during flowering, a point where generally, a plant needs MORE nutes, they just randomly start to burn... I also have purple edges on some newer growth, in addition to the burnt tips and spotting... I'm certainly not an expert, but according to the all knowing Google (lol) it would seem to be a cal-mag deficiency, in addition to a phosphorus deficiency...

 

[Lexstar]

It is a dead giveaway when the tips of the leaves look burnt, it’s nute burn. If you spill drops of your nutrient water on the leaves it will cause them to spot like that. Never sweat it but don’t make a habit of it. In excess it will kill your precious. I have no experience with the Gaia Green nutrient line so I’m no help there. I’m switching my nutrients to Grow Dots this next grow.

 

[SMCelite36]

It is a dead giveaway when the tips of the leaves look burnt, it’s nute burn. If you spill drops of your nutrient water on the leaves it will cause them to spot like that. Never sweat it but don’t make a habit of it. In excess it will kill your precious. I have no experience with the Gaia Green nutrient line so I’m no help there. I’m switching my nutrients to Grow Dots this next grow.

Would nute burn also cause purpling of the leaves and stems?

 

[Delps8]

Would nute burn also cause purpling of the leaves and stems?

Purple stems may be genetic but they're also found when VPD is so out of whack that there's either a K or P issue. I heard it mentioned in a video I listened to over the weekend but I don't remember which one it was.

[runs a search through his text files of notes from YT vids]

Got it - "Purple stems is probably phosporus or just a nute uptake issue."

Here's the notes, in toto. typos and all.

VPD
Nutrition
CO2/Light intensity

Should not have a delta of > 5° or 5% for optimal growth

What values at what stage of groth

Measured in KPa

Clones 0.7 to 1.0
Depends on the cultivar

If you see yellowing - not wilting and yellowing - but it's stiff due to turgidity. Yo'll see a little bit of nitrogen deficiencty.
Increase VPD so it moves more nutes through the system.
The plant will take off so shift to a .9 or a 1.0

In veg, stay at 0.8 to 1. Varies with medium
Coc behaves differently in terms of response because it wants to hold it wicks very quickly.
Not all media are equivalent.


FLower
At end of veg, move to 1.1. IN flower, got to 1.2. In general 1.2 to 1.4 is more than enough stress and pressure on the plant but it's cultivar dependent. Anything over a 2 and you're inducing plant stress for 99% of coultivars and cultivators.

a soil with clay or poor aeration behaves very differently than, say, hydro.

Most facilities can't ekkp to 2° how do we work around that

Lighting intensity is expensive, same with heat

RH is cheaper to control.

It's easier for a split to drop temp than it is to lower humidity.
A split can't do 60 and 60. That's cold stressing.
pocket humidifier vs dx
The split can't drop RH.
Adjusting RH is cheaper.

Do oscilating fans pose any danger.
Only if they grow into the fans
Biggest risk is excessive

Taco down is too high VPD
Same as wind burn
Plants, in general, leaves should be lightly dancing. Barely flutter. Definitely not sway

Terpens play a bigger role than cannabanoids.

VPD is extermely important in all forms of cultivation.

How important is it to breath whether you eat steak or mac and cheese.

Do not use lady bugs under any conditions

Like Govee. Knows Pulse.

Use three humidistats.

Sative vs indica - they do not exist
Look at terpene profiles.

Purple stems is probably phosporus or just a nute uptake issue.

75 to 80° with 10° swing at night with RH 50-65 in veg and 45 to 55 in flower.

if you were to take those parameters and put them into a VPD calculator, your VPD is way too high. In flower, you are ripping way too much moister out of those plants at 75-80 and 45%

Even 55 is way to low, you should be running at 65 mosst likely for the majority of your flowering period and then drop it down to 55 at the ver very end of your flowerig period. The last couple of weeks."

HTH

 

[SMCelite36]

Purple stems may be genetic but they're also found when VPD is so out of whack that there's either a K or P issue. I heard it mentioned in a video I listened to over the weekend but I don't remember which one it was.

[runs a search through his text files of notes from YT vids]

Got it - "Purple stems is probably phosporus or just a nute uptake issue."

Here's the notes, in toto. typos and all.

VPD
Nutrition
CO2/Light intensity

Should not have a delta of > 5° or 5% for optimal growth

What values at what stage of groth

Measured in KPa

Clones 0.7 to 1.0
Depends on the cultivar

If you see yellowing - not wilting and yellowing - but it's stiff due to turgidity. Yo'll see a little bit of nitrogen deficiencty.
Increase VPD so it moves more nutes through the system.
The plant will take off so shift to a .9 or a 1.0

In veg, stay at 0.8 to 1. Varies with medium
Coc behaves differently in terms of response because it wants to hold it wicks very quickly.
Not all media are equivalent.


FLower
At end of veg, move to 1.1. IN flower, got to 1.2. In general 1.2 to 1.4 is more than enough stress and pressure on the plant but it's cultivar dependent. Anything over a 2 and you're inducing plant stress for 99% of coultivars and cultivators.

a soil with clay or poor aeration behaves very differently than, say, hydro.

Most facilities can't ekkp to 2° how do we work around that

Lighting intensity is expensive, same with heat

RH is cheaper to control.

It's easier for a split to drop temp than it is to lower humidity.
A split can't do 60 and 60. That's cold stressing.
pocket humidifier vs dx
The split can't drop RH.
Adjusting RH is cheaper.

Do oscilating fans pose any danger.
Only if they grow into the fans
Biggest risk is excessive

Taco down is too high VPD
Same as wind burn
Plants, in general, leaves should be lightly dancing. Barely flutter. Definitely not sway

Terpens play a bigger role than cannabanoids.

VPD is extermely important in all forms of cultivation.

How important is it to breath whether you eat steak or mac and cheese.

Do not use lady bugs under any conditions

Like Govee. Knows Pulse.

Use three humidistats.

Sative vs indica - they do not exist
Look at terpene profiles.

Purple stems is probably phosporus or just a nute uptake issue.

75 to 80° with 10° swing at night with RH 50-65 in veg and 45 to 55 in flower.

if you were to take those parameters and put them into a VPD calculator, your VPD is way too high. In flower, you are ripping way too much moister out of those plants at 75-80 and 45%

Even 55 is way to low, you should be running at 65 mosst likely for the majority of your flowering period and then drop it down to 55 at the ver very end of your flowerig period. The last couple of weeks."

HTH

Yeah, the Internet is so damn confusing, just an endless loop of contradictory information, it's so hard trying to learn on your own unless you can bring somebody who actually knows what they're talking about into your grow room and have them say that without a shadow of a doubt that "this" or "that" or multiple factors are playing a role in the overall issue or issues that you're experiencing... My temps fluctuate anywhere between 76 degrees and 80 degrees and no matter how many vents I open, fans I crank up, or what setting my exhaust fan is on, it just won't go down, and as far as humidity goes, every source available says that mid 30% or so is "optimal" that way you can avoid mold issues during flowering... I'm trying to get my environment dialed in, but it's seemingly unrelenting, it's frustrating as hell... lol

 

[Delps8]

Yeah, the Internet is so damn confusing, just an endless loop of contradictory information, it's so hard trying to learn on your own unless you can bring somebody who actually knows what they're talking about into your grow room and have them say that without a shadow of a doubt that "this" or "that" or multiple factors are playing a role in the overall issue or issues that you're experiencing...

If you want that, hire a consultant. This guy wrote a product called HydroBuddy which helps growers formulate their own nutes. He might be a good resource.

Re. the link I posted - the people in the video are experts. Bruce Bugbee is one of the leading researchers on light and nutrients for plants in the world.

You get out of it what you put into it. If you stop at "It's confusing" then you won't have learned much.

My temps fluctuate anywhere between 76 degrees and 80 degrees and no matter how many vents I open, fans I crank up, or what setting my exhaust fan is on, it just won't go down, and as far as humidity goes, every source available says that mid 30% or so is "optimal" that way you can avoid mold issues during flowering... I'm trying to get my environment dialed in, but it's seemingly unrelenting, it's frustrating as hell... lol

76 to 80 is an excellent range to work in.

If you find sources that say that growing a plant in 30%RH is optimal, disregard their advice. That's inane. There's simply no way to support that, based on how plants function.

At 30% and 80°, the amount of water your plants need to expel, and therefore uptake, is huge compared to, say 50%. We know that because we can look at a VPD chart that has the calculations driving it.

80 and 30 is desert environment. Vegetation exists in the desert because it's highly adapted to the environment.

You do realize, right, that people in the desert have to drink a lot of water to they die of thirst. I mean, you do get that right?

Cannabis grows in moderate temps and moderate RH - 75 and 60 is a good combo.

I've posted a VPD chart that's a mirror og every other VPD chart out there. There's no major difference in them because they're describing how plants work.

You can follow it or not. I don't care but your plants live and die by it.

If you continue to expose your plants to a harsh, desert like environment, the best I can hope for is that you kill them quickly so that you can start over again, taking a better approach.

 

[SMCelite36]

If you want that, hire a consultant. This guy wrote a product called HydroBuddy which helps growers formulate their own nutes. He might be a good resource.

Re. the link I posted - the people in the video are experts. Bruce Bugbee is one of the leading researchers on light and nutrients for plants in the world.

You get out of it what you put into it. If you stop at "It's confusing" then you won't have learned much.


76 to 80 is an excellent range to work in.

If you find sources that say that growing a plant in 30%RH is optimal, disregard their advice. That's inane. There's simply no way to support that, based on how plants function.

At 30% and 80°, the amount of water your plants need to expel, and therefore uptake, is huge compared to, say 50%. We know that because we can look at a VPD chart that has the calculations driving it.

80 and 30 is desert environment. Vegetation exists in the desert because it's highly adapted to the environment.

You do realize, right, that people in the desert have to drink a lot of water to they die of thirst. I mean, you do get that right?

Cannabis grows in moderate temps and moderate RH - 75 and 60 is a good combo.

I've posted a VPD chart that's a mirror og every other VPD chart out there. There's no major difference in them because they're describing how plants work.

You can follow it or not. I don't care but your plants live and die by it.

If you continue to expose your plants to a harsh, desert like environment, the best I can hope for is that you kill them quickly so that you can start over again, taking a better approach.

You got me all wrong my guy, I really appreciate your advice, you definitely sound more than competent, and I'm very persistent, getting frustrated is just part of my process, it just adds to my motivation, I've come far too far to just throw my hands in the air and give up... More humidity shouldn't be hard, and from the little bit of knowledge I have about mold, as long as there is an even exchange of air, and it's not left to stagnate, mold shouldn't be an issue... Good looking out, I suppose I have some work to do...

 

[SMCelite36]

You got me all wrong my guy, I really appreciate your advice, you definitely sound more than competent, and I'm very persistent, getting frustrated is just part of my process, it just adds to my motivation, I've come far too far to just throw my hands in the air and give up... More humidity shouldn't be hard, and from the little bit of knowledge I have about mold, as long as there is an even exchange of air, and it's not left to stagnate, mold shouldn't be an issue... Good looking out, I suppose I have some work to do...

And on another note, are cannabis cultivation consultants a thing?... If so, I may have to look into that...

 

[OGpapa]

Lots of consultants here at 420!

Free advice, right or wrong. All day everyday!

You got this!!!!!

 

[Delps8]

You got me all wrong my guy, I really appreciate your advice, you definitely sound more than competent, and I'm very persistent, getting frustrated is just part of my process, it just adds to my motivation, I've come far too far to just throw my hands in the air and give up... More humidity shouldn't be hard, and from the little bit of knowledge I have about mold, as long as there is an even exchange of air, and it's not left to stagnate, mold shouldn't be an issue... Good looking out, I suppose I have some work to do...

I'm good writing software. This growing stuff is new to me (three years) but "it's all written down" (that date's me, eh?) so it might take a little while but you can always find solid sources.

Mold - do not speak of such!

My crop a year ago went in the dumpster. That hurt.

Yeh, get that RH up and your plants will thank you for it.

 

[Delps8]

And on another note, are cannabis cultivation consultants a thing?... If so, I may have to look into that...

Absolutely!

Check YT for Harley Smith. His nickname is "Chops", IIRC, because he has big, very old school sideburns that run into his beard.

The site I recommended is $150 per hour which is very reasonable. Drop him an email and see what he says. Nothing ventured, nothing gained, right?

Here's one for you - check out my early grows where I pissed and moaned about chasing pH because I was following the shitty advice on "the Wonder Chart", as I call it, about what to do when pH is dropping. It advises the grow to keep dropping PPM until pH stabilizes. I was running around with my hair on fire because no one had an answer. Until one data, my good man @FelipeBlu was kind enough to send me a simple PM that explained that dropping pH in early flower is completely expected and it happens because of how the plant is taking up nutes out of the res. I wasted hours of my life (at $125 per hour) when, for $150, I could have gotten the answer and a lot of knowledge to boot in a matter of minutes.

Sure, you can accumulate knowledge but at what cost? It's much easier to pay someone who has the knowledge. In some roles, we refer to those people as "teachers", right? A consultant is someone with more detailed knowledge, who is hired on a temporary or ad hoc basis, and is hired for a specific audience.