Anyone know what’s going on here

[twentyeight.threefive]

I've been having this issue w Coco under LEDs for a while and after chaising my tail I came to the conclusion that my high VPD was causing my plants to uptake too much calcium during transpiration, causing Magnesium and Potassium deficiencies.

The first sign was plants that were perfectly happy vegging under my T5s, would droop and curl badly just hrs after they were put under the LEDs. Then I would get the yellow spotting on the upper leaves, leading to full on interveinal chlorosis. (Mag Deficiency) Lower leaves would yellow and scorch from the edges inward, stems and petioles would turn purple and growth would slow to a crawl.(Potassium Deficiency) I was also getting tip burn at insanely low EC levels, but the plants would always show those same symptoms yours have.

I stopped my calmag supplementation for 2 weeks, raised my temps and humidity to about 80F, 70%Rh, and everything is finally pulling around and giving me lush green growth again. After doing tons of reading and research and pulling my hair out for months, this was the solution for me. It was all because my low humidity. Was never a problem under HPS or T5s, but proper LEDs made them freak out until I got VPD in check.

This might not be the case for you, but figured I'd share what I've found since I see the same symptoms with your young plants

You made multiple changes at once. You can't be certain which change actually made the difference.

 

[StonedAgeGrower]

You made multiple changes at once. You can't be certain which change actually made the difference.

As I said this was the best conclusion I could draw after doing several months worth of reading and researching about the role of calcium and High VPD environments. Reducing Calcium for 2 weeks and bringing the VPD into proper ranges were the only changes made at the same time, and showed rapid improvement. To further my thought that increased Ca uptake due to high VPD was the culprit, now that my VPD is in range, my plants are now handling my previous nutrients, cal mag included.

I thought I was chasing a constant K and Mg deficiency, but really the increased uptake of Ca from the plants over-transpiration due to low RH was locking out K and Mg. They like their normal dose of calcium now and Mg and K def has gone away.

I didn't have tissue analysis or anything like that done to scientifically prove that was the issue, but I'm making my best educated guess

 

[twentyeight.threefive]

As I said this was the best conclusion I could draw after doing several months worth of reading and researching about the role of calcium and High VPD environments. Reducing Calcium for 2 weeks and bringing the VPD into proper ranges were the only changes made at the same time, and showed rapid improvement. To further my thought that increased Ca uptake due to high VPD was the culprit, now that my VPD is in range, my plants are now handling my previous nutrients, cal mag included.

I didn't have tissue analysis or anything like that done to scientifically prove that was the issue, but I'm making my best educated guess

High VPD causing high transpiration will cause increase the uptake of all nutrients. You could have fixed the issue with reducing your EC or decreasing the VPD.

 

[StonedAgeGrower]

High VPD causing high transpiration will cause increase the uptake of all nutrients. You could have fixed the issue with reducing your EC or decreasing the VPD.

All nutrients are not uptaken by the plant equally during transpiration, however Calcium does move much more rapidly during transpiration. You are right about the fixes, but the actual antagonist of all the issues was Calcium in my case.

Even lowering EC to .6 and seeing tip burn on large plants.

Like I said I now feed calcium at regular rates, but while I was getting my VPD in check, cutting my dose of CalMag showed very rapid improvement. I'm sure getting VPD right had much to do with that as well

 

[twentyeight.threefive]

All nutrients are not uptaken by the plant equally during transpiration, however Calcium does move much more rapidly during transpiration. You are right about the fixes, but the actual antagonist of all the issues was Calcium

So which nutrients are taken up more than others?

 

[StonedAgeGrower]

So which nutrients are taken up more than others?

From what I was researching in Canna and Agriculture studies, calcium will be taken up more readily than other nutrients when there is Low humidity/High VPD and that uptake of Ca can antagonize the uptake of K and Mg. I'm assuming you think this is incorrect?

 

[rkymtnman]

Anyone else agree?

can you post up the labels of your nutes?

 

[twentyeight.threefive]

From what I was researching in Canna and Agriculture studies, calcium will be taken up more readily than other nutrients when there is Low humidity/High VPD. I'm assuming you think this is incorrect?

No, I'm asking since you stated it as a fact otherwise. I was hoping for information proving your statement.

 

[StonedAgeGrower]

No, I'm asking since you stated it as a fact otherwise. I was hoping for information proving your statement.

I said from the get go that these were my conclusions after researching and trial and error in my own garden. I never said these were facts. I will be happy to find and share the papers I was reading so you can draw your own conclusions.

 

[Coco-garden]

I've been having this issue w Coco under LEDs for a while and after chaising my tail I came to the conclusion that my high VPD was causing my plants to uptake too much calcium during transpiration, causing Magnesium and Potassium deficiencies.

The first sign was plants that were perfectly happy vegging under my T5s, would droop and curl badly just hrs after they were put under the LEDs. Then I would get the yellow spotting on the upper leaves, leading to full on interveinal chlorosis. (Mag Deficiency) Lower leaves would yellow and scorch from the edges inward, stems and petioles would turn purple and growth would slow to a crawl.(Potassium Deficiency) I was also getting tip burn at insanely low EC levels, but the plants would always show those same symptoms yours have.

I stopped my calmag supplementation for 2 weeks, raised my temps and humidity to about 80F, 70%Rh, and everything is finally pulling around and giving me lush green growth again. After doing tons of reading and research and pulling my hair out for months, this was the solution for me. It was all because my low humidity. Was never a problem under HPS or T5s, but proper LEDs made them freak out until I got VPD in check.

This might not be the case for you, but figured I'd share what I've found since I see the same symptoms with your young plants

Wow very informative man much appreciated. I have an ac infinity in-line with a humidifier so my environment is just about perfect. I dosed them with some calmag gunna see how they look tmr and if they perk back up. If not then the next solution that I can think of would be that my ph is a bit high.

 

[StonedAgeGrower]

Wow very informative man much appreciated. I have an ac infinity in-line with a humidifier so my environment is just about perfect. I dosed them with some calmag gunna see how they look tmr and if they perk back up. If not then the next solution that I can think of would be that my ph is a bit high.

Yeah, if your VPD is in check, and runoff EC is in range, Ph should be the next place to look.

I've been looking at those Ac Infinity Fans with the Temp and Humidity controller. How do you like yours?

 

[Coco-garden]

Yeah, if your VPD is in check, and runoff EC is in range, Ph should be the next place to look.

I've been looking at those Ac Infinity Fans with the Temp and Humidity controller. How do you like yours?

Mine works great it kicks on about every 3 to 5 mins for a min or 2 so I have plenty of fresh air coming in. My run off ec was at about the same as my intake so I don’t think that was really the problem. Only other then I can think of if the dose of Calmag doesn’t work is that I need to adjust my ph. Just outta curiosity what ph do you run your coco at? I’m at about my 4th node.

 

[StonedAgeGrower]

Mine works great it kicks on about every 3 to 5 mins for a min or 2 so I have plenty of fresh air coming in. My run off ec was at about the same as my intake so I don’t think that was really the problem. Only other then I can think of if the dose of Calmag doesn’t work is that I need to adjust my ph. Just outta curiosity what ph do you run your coco at? I’m at about my 4th node.

I think I'm definitely going to have to get one of those. Would go a long way in keeping the environment just right.

As for ph, I used to always feed at 5.8 when I was under HPS, but under LED I'm finding they like it a tad higher. I let it drift over the course of 5-7 days from 5.8-6.2