LED and Calmag issues.

twentyeight.threefive

twentyeight.threefive

Well-Known Member
strongbow19 said:
Would just like to say that this is one of the most informative threads on LED growing on the whole internet.

I recently started up a grow and had between 18 C and 20 C throughout the 4 weeks veg and they started showing heavy tiger stripes and the start of brown spots a few days ago, and I went out and bought a heater after discovering this thread. I am now having day time temps of around 25 26 max and running the exhaust on stop and go to reduce usage of heater and also have the heater on a temp controller and then keeping the humidity between 62 and 76 during the day. 17 degrees and 60 humidity at lights off.

But now, after I changed the environment up a bit like mentioned above they are now getting burned tips and also their EC runoff is now a bit higher than the input, where it literally was the opposite when I ran the low shit temps I would give 1.6 EC and they would have a run off 1.3. Now it's 1.5 input and 1.7 1.8 run off. I saw a comment on here that a guy also had opposite reaction on EC when he tuned his VPD for the better.

Temp of leaf surface is 1 degree less than ambient.

They are clones from mothers that was fed 1.6 EC all their life.

My question is why? I thought they would now embrace even more light and use better nutes. (Not that I changed the light distance or anything.)

Never thought I'd have so many pit falls staring up a LED grow room and so many things to buy, it's sad really.
Have been growing outdoors in 100% coco since 2014. Have never tried my hands at indoor.

What should I do now, any input would be appreciated.
Click to expand...
How often are you feeding that 1.5 EC feed?
 
G

GrodanLightfoot

Well-Known Member
3rd Monkey said:
So, there's been some correlation between using LED lights and calmag issues, particularly a lack of calcium and sometimes magnesium.

I've been doing some testing with tomato plants under an LED. I was finally able to replicate the issue.

Now, what I have found is that it's not really a Calmag issue at all, it's a potassium issue. Let me explain.

I ran 6 tomatoes under an LED until I got the issue to arise. I fed extra calmag to 2, dropped potassium to 1/2 and cut calmag in 2, and dropped potassium and calmag in 2 of them to 1/2.

The 2 with the extra calmag were fine until a full nute feeding, then back to calcium issues.

The 2 with reduced potassium and cut calmag, did better than full nutes and full calmag. Still issues.

The 2 with reduced potassium and barebones calmag seemed to alleviate the symptoms completely and are now growing healthy again.

I don't have lab equipment and I didn't document it, which I should have but had no idea what I was trying to do yet lol. However, in my testing, it appears that it's not a lack of calmag from the LED, but an excess of K.

I don't know if it deals with spectrum or par or whatever, but I would like some input from anyone who can possibly explain this, if it can be explained.
Click to expand...

It's a Boron issue. You're locking out boron. You can't add potassium calcium or magnesium without Boron. You didn't need to add calmag what soever. There is no such thing as a calcium deficiency with cannabis. You'd have to intentionally assembled a medium and fertigation completely devoid of all forms of calcium.

Sorry but if you grow with cannabis nutes, you are working against yourself. None of the shit on the hydro store shelf makes sense for cannabis under led. I spoke with Athena recently.. My God people... These people are the experts of Cannabis???
 
twentyeight.threefive

twentyeight.threefive

Well-Known Member
GrodanLightfoot said:
It's a Boron issue. You're locking out boron. You can't add potassium calcium or magnesium without Boron. You didn't need to add calmag what soever. There is no such thing as a calcium deficiency with cannabis. You'd have to intentionally assembled a medium and fertigation completely devoid of all forms of calcium.

Sorry but if you grow with cannabis nutes, you are working against yourself. None of the shit on the hydro store shelf makes sense for cannabis under led. I spoke with Athena recently.. My God people... These people are the experts of Cannabis???
Click to expand...
Ignore this entire post.
 
bk78

bk78

Well-Known Member
GrodanLightfoot said:
It's a Boron issue. You're locking out boron. You can't add potassium calcium or magnesium without Boron. You didn't need to add calmag what soever. There is no such thing as a calcium deficiency with cannabis. You'd have to intentionally assembled a medium and fertigation completely devoid of all forms of calcium.

Sorry but if you grow with cannabis nutes, you are working against yourself. None of the shit on the hydro store shelf makes sense for cannabis under led. I spoke with Athena recently.. My God people... These people are the experts of Cannabis???
Click to expand...
Second to ignore this garbo
 
strongbow19

strongbow19

Member
strongbow19 said:
Would just like to say that this is one of the most informative threads on LED growing on the whole internet.

I recently started up a grow and had between 18 C and 20 C throughout the 4 weeks veg and they started showing heavy tiger stripes and the start of brown spots a few days ago, and I went out and bought a heater after discovering this thread. I am now having day time temps of around 25 26 max and running the exhaust on stop and go to reduce usage of heater and also have the heater on a temp controller and then keeping the humidity between 62 and 76 during the day. 17 degrees and 60 humidity at lights off.

But now, after I changed the environment up a bit like mentioned above they are now getting burned tips and also their EC runoff is now a bit higher than the input, where it literally was the opposite when I ran the low shit temps I would give 1.6 EC and they would have a run off 1.3. Now it's 1.5 input and 1.7 1.8 run off. I saw a comment on here that a guy also had opposite reaction on EC when he tuned his VPD for the better.

Temp of leaf surface is 1 degree less than ambient.

They are clones from mothers that was fed 1.6 EC all their life.

My question is why? I thought they would now embrace even more light and use better nutes. (Not that I changed the light distance or anything.)

Never thought I'd have so many pit falls staring up a LED grow room and so many things to buy, it's sad really.
Have been growing outdoors in 100% coco since 2014. Have never tried my hands at indoor.

What should I do now, any input would be appreciated.
Click to expand...
Hi again guys.

My plants are looking better, regarding the mag and cal issue and also regarding the nutrient burn after changing the temps for the better. The run off EC is also now the same as input. BUT now, I am having early signs of nitrogen toxicity, drooping leaf tips, not all of them, here and there and also easy broken stems.

I've read up and they say to flush your plants with water and not give nutes again for a while, but that's impossible for me because I am in 100% coco.
This happened because it is now hotter and the plant is taking up more water than before and therefor my guess also taking up more nitrogen.

Quote:
Nutrient Burn and Worsening in Heat
" Nutrient burn goes hand in hand with nitrogen toxicity so that is also an important symptom. In higher temperatures, the leaves may claw more as they drink more water to tackle the heat which results in absorbing more nitrogen. "

So I really don't know what to do now, it's not like I'm running the high temps like suggested in this thread 28 - 30 C. I am at around 25 26 C max and at lights off 18 C.

I have been using these nutes for a decade outdoors in coco without ever seeing such symptoms. They say to please use equal parts in my case of nutes, so I can't really experiment.

What is there left to do? I can't possibly lower the EC more? Like I said before they came from mothers with a EC of 1.6 and I got deficiency issues when I fed them 1.2 EC early in veg. I am 5 days away from flip, any inputs would be appreciated.
 
twentyeight.threefive

twentyeight.threefive

Well-Known Member
strongbow19 said:
Hi again guys.

My plants are looking better, regarding the mag and cal issue and also regarding the nutrient burn after changing the temps for the better. The run off EC is also now the same as input. BUT now, I am having early signs of nitrogen toxicity, drooping leaf tips, not all of them, here and there and also easy broken stems.

I've read up and they say to flush your plants with water and not give nutes again for a while, but that's impossible for me because I am in 100% coco.
This happened because it is now hotter and the plant is taking up more water than before and therefor my guess also taking up more nitrogen.

Quote:
Nutrient Burn and Worsening in Heat
" Nutrient burn goes hand in hand with nitrogen toxicity so that is also an important symptom. In higher temperatures, the leaves may claw more as they drink more water to tackle the heat which results in absorbing more nitrogen. "

So I really don't know what to do now, it's not like I'm running the high temps like suggested in this thread 28 - 30 C. I am at around 25 26 C max and at lights off 18 C.

I have been using these nutes for a decade outdoors in coco without ever seeing such symptoms. They say to please use equal parts in my case of nutes, so I can't really experiment.

What is there left to do? I can't possibly lower the EC more? Like I said before they came from mothers with a EC of 1.6 and I got deficiency issues when I fed them 1.2 EC early in veg. I am 5 days away from flip, any inputs would be appreciated.
Click to expand...
Why can't you lower the EC?

How often are you feeding them?
 
strongbow19

strongbow19

Member
I will post pics of the leaf tips later. But honestly as you can see the plants are behaving differently after adjusting the humidity and temps for the better. According to this thread.

It's a custom build light by a reputable company where I live with samsung 561c diodes and a meanwell driver. Total 700watts. Space 1.5mx1.5m.
Basically based on the older HLG boards, when I mean older, 3 years ago. But the light is new. They are 16 inches away from the tops. The builder and creator himself runs it 12 inches full power from early veg until harvest with great success? I downloaded the photone app on the appstore but it comes to something like 320 PPFD or 20000 lux which is pretty fuckin weak, but I must say I have a budget $100 phone.

I am at 1.4 1.5 EC max. All I can do is lower the EC to 1.3 the next watering and just hope that the plants will ride it out and adjust. But still in my mind if the plants take up more water and nutes when the temps are raised I would've thought they would want even more nutes (stronger EC), if they are using more ? ? ?
 
Last edited:
strongbow19

strongbow19

Member
twentyeight.threefive said:
What lights are you using? How close are they and what power?

Pics?
Click to expand...
First picture of what my plants looked like in early veg being fed 1.2EC over longer period like 2 weeks. Early potassium deficiency and other, basically they were real hungry and when I upped the EC to 1.6 stuff got way better. The second picture is what my plants look like now after I upped the temps and corrected the cal and mag deficits it had due to the 17C daytime temps. I didn't take pics at that time. The third and fourth pics show the drooping leaf tips now.
IMG_20220807_105942.jpgIMG_20220827_155138.jpgIMG_20220828_161728.jpgIMG_20220828_161831.jpg
 
twentyeight.threefive

twentyeight.threefive

Well-Known Member
strongbow19 said:
First picture of what my plants looked like in early veg being fed 1.2EC over longer period like 2 weeks. Early potassium deficiency and other, basically they were real hungry and when I upped the EC to 1.6 stuff got way better. The second picture is what my plants look like now after I upped the temps and corrected the cal and mag deficits it had due to the 17C daytime temps. I didn't take pics at that time. The third and fourth pics show the drooping leaf tips now.
View attachment 5188675View attachment 5188676View attachment 5188678View attachment 5188679
Click to expand...
I would raise the lights or turn the power down. Also reduce the nitrogen in your feed.

Also pictures with the grow lights off are best.
 
strongbow19

strongbow19

Member
twentyeight.threefive said:
I would raise the lights or turn the power down. Also reduce the nitrogen in your feed.

Also pictures with the grow lights off are best.
Click to expand...
But can you explain to me what turning down the power would do to fix the nitrogen problem?

What I am gathering is I need to lower my EC now that I have improved/upped the temps, seeing that they now have improved nutrient uptake/more ?

The question is why didn't the plants nute burn at 18C days with the lights at the same height the whole time. In fact most of that time they had a lower run off EC than input by 0.3 - 04 EC. Mind boggling, but I need to know why.
 
C

ComfortCreator

Well-Known Member
strongbow19 said:
But can you explain to me what turning down the power would do to fix the nitrogen problem?

What I am gathering is I need to lower my EC now that I have improved/upped the temps, seeing that they now have improved nutrient uptake/more ?

The question is why didn't the plants nute burn at 18C days with the lights at the same height the whole time. In fact most of that time they had a lower run off EC than input by 0.3 - 04 EC. Mind boggling, but I need to know why.
Click to expand...
I have not followed every post but VPD will alter how much nutes they take in. If the humidity is high they act differently than at a moderate level, same for temperature. EC will determine what they drink but they also are highly affected by the VPD (temp / humidity).

A very dry room requires them to drink more...a moist room they drink less quickly. Temp alters the rate also.
 
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