Mg??

[f-e]

I always get this under LED. It generally starts in the slightly more humid areas. Middle larger leaves, working upwards. It looks like Mg but no amount of Mg stops it. First I see red leaf stems, then slight lines, ultimately this. The red could be just stress, but has general associations with N P and Mg. I also have what I see as premature aging, an Mg trait. I'm looking towards P though, which helps Mg. Even enough Mg to burn them wasn't helpful.

I thought I would put up a pic, just to see if people have seen it from other issues, or just want to say Mg.

I have about 90ppm K from my food, but it's coco so call it near 180ppm. Calcium around 65ppm. A good dry out did spread it, when it had been advancing slowly without the hard dry back. So it could be that K Mg Ca triangle still.

The photo is a good colour rendition. The dark green comes as the stripes do. The unaffected leaves are a reasonable colour.

 

[gmanwho]

looks more like calcium deficiency to me. but Mg calcium and boron go hand and hand. if i remember correct just increasing one of those 3 creates an imbalance. An boron is a fraction of the equation. Calcium..

to help diagnose you should post your grow setup details, heat humidity medium container size nutrients watering methods genetics etc etc...

 

[negative37dBA]

Really need some conditions and numbers to help you there buddy. We don't even know what you are using to feed...
I have added some heat to my area to pick up leaf surface temp, helps with transpiration. These LEDs will bring out the defs quick because you are running the plant hard. You could raise or dim the light a bit to help with the amount of PPFD it is getting.
Peace, negative.

 

[f-e]

I did try calcium by foliar spray. Just over an area, and saw no change. If anything, I have been reducing calcium to hold this off and seeing limited but positive results. In early transition I sometimes see a whiter stripe that breaks out into calcium spotting. Not this yellowing. However, I don't have a better answer, so I will keep this in mind. My best veg under LED was with high P and Ca around 200ppm. It still started to happen though.

I'm in very small containers of coco, dripping to waste twice a day, as I can't get through on just one a day. Temperature seems to not matter, but about 28 at the moment. RH just under 60 but again, little difference is seen as that changes. Yet the issue starts where a little recycled air creeps in, not the fresher air route. Immeasurably different, but I think a little more CO2 if anything.

I have sodium on my mind, as it's coco and I revolve around issues with K Mg and Ca in the spotlight. Feeding 6 a day to 40% runoff didn't help. I have been through quite a lot of trials.


Ultimately, I'm heading out of coco. I have seen nothing to convince me it performs well enough for LEDs. Others have walked the same path. I like to fix things or at least find the problem though. However, I think it's just coco. It works in big tubs or with lower lighting, but I have not seen a meaningful grow with the stuff under LED. Perhaps someone can point me to one. I just know people that moved away after buying LEDs

 

[f-e]

I have never seen N look like that, or start in the middle. I see typical N signs at the bottom, unrelated to me issue.

Mg pics around the net, often look just like mine. The same pics are sometimes used for Iron. Here zinc looks possible. I do have iron I can add, but iron isn't particularly mobile.

It all points to Mg, but Mg won't fix it. Which takes me to P as an aid, or excess K or Ca.

Not enough Ca is something I have tried about as exhaustively as not enough Mg.


I have used a few different feeds. No change. Though either high or low EC promotes it. Meaning lockout or not enough is easy to accomplish. Runoff tests have boron in range.

 

[negative37dBA]

Nice info....the sodium would be not good if it is in any quantity. I have seen people move away from coco to when using leds. Are you able to switch to hydro? I have been having good luck with high power LEDs in RDWC. I am using Jacks 3-2-1 for food. I find it very easy to customize to the plants needs. Have some of the best looking plants of my life with Jacks. It is super cheap to.
Have a great day all. Peace, negative.

 

[flylowgethigh]

This latest run (#3) I am using recycled soil. I did add some alfalfa and kelp to the soil and didn't let it cook very long before I up-potted into it. It was warm. I also have been using a lot of cal-mag throughout the cycle. This is the first run to have the leaves look beautiful with no discoloration at all. Plants have grown too tall as a result.

Living soil is sure easy. Get the spark going and sit back, water n watch.

 

[FletchF.Fletch]

It looks like Mn deficiency. Drop your ph a tick and bump up your Manganese. Or just let them watch some Japanese cartoons. Get it? Manga----nese!!!

 

[VerdantGreen]

Probably won't help, but i did an experiment with one of my plants where i suspected that root-binding was causing deficiencies and making the stems/petioles go red. re-potting cured it - posts 305 and 308
https://www.icmag.com/forum/marijua...y-post-your-rols-pics-here/page21#post8084077

 

[VerdantGreen]

double post

 

[f-e]

I'm not particularly root bound, despite the small pots. I did use bigger ones, which while still small, offered little but aeration problems for me.
Changing my story a little, I did see the mild beginnings of this under HID and a higher RH stopped it. It was every time I put new plants in, I had to raise the RH or see stripes and stunting. It may of been something else though, as it never got this far. Looking back, a lower EC might of been as much use as the higher RH, but it's historic info now.

I see this at all pH levels. For a while my pH was dropping to 5, but the last couple of runs it's been climbing past 7. RO water, so easy to push about. Not a real gauge of root zone pH. I know the swing from low to high is my use of excess feed, then low feeding. As I have been trying everything.

Mn Fe Zn... They are all in canna trace mix which I keep around. I just dropped the calmag and switched to a trace increase. It will go one way or the other?

My usual feed, as used on this run, is Ionic. They list Mg as in the bottle, but don't say how much. I know they don't need to say the actual amount if under a certain threshold. I read it once, but search as I may, I can't find the threshold written anywhere. However I can't have much and my Ca is just 25ppm with this tank. As I'm half dosing the feed, to get the calmag down.


I have never had so many problems as I have the last couple of years. Elsewhere in bigger pots with a res of runoff below them to drink, the problem doesn't exist.

I'm trying to move. At which point I'm going flood/drain pebbles. I must be really quiet here though, so I'm stuck with the drip. Though just today I discovered a new pump that's remarkably quiet. Silent really. No vibration even holding it. I think it's a 3 phase DC signwave drive.

 

[PolyChucker]

Any veining I use calmag or calmag plus. But all nutrients are relative. The dark leaf edge looks like you have a lot of nitrogen. Need to find balance of nutrients. Could also be caused by ph lockout

I use neutral potting soil, start out with 5-1-1 to 10-2-2 for veg. Start giving 4ml calmag if veining develops. I repot when the canopy is larger than pot diameter.

 

[f-e]

I guess there is a root bound like issue, as a bigger pot would help. It's more than that though, as it's dry downs that peak the root EC that really move the problem forward. So it's not a deficiency as such, but a lock out. Though adding more, such as a larger pot, would alleviate the problem.

I think the excess sodium of coco is likely a key issue. Nothing else is actually high, by any measure, except perhaps K, which again, is coming from the coco

I'm still looking for good CoCo/LED grows. As time goes by, I become more convinced coco is out of it's depth with the speeds LEDs can promote.

 

[VerdantGreen]

Yeah it's hard when there are so many variables. You need the nutrition in the soil or irrigation... but if you are rootbound this can stop the plant accessing the nutes that are there. Also if the medium is too dry, the roots can't uptake certain nutrients. I used to get blossom end-rot on my tomatoes - which is caused by calcium deficiency... there was plenty of calcium in the soil.. but i wasn't watering them enough for the roots to uptake the calcium.
GL
VG

 

[bsgospel]

My guess is micros. Correct me if I'm wrong but that leaf looks like new growth?
If you're fine on Ca and Mg then my brain goes to some combo of micros. Do you have any pics of this issue on the plant (no plucked leaf/as is?)

 

[jackspratt61]

I guess there is a root bound like issue, as a bigger pot would help. It's more than that though, as it's dry downs that peak the root EC that really move the problem forward. So it's not a deficiency as such, but a lock out. Though adding more, such as a larger pot, would alleviate the problem.

I think the excess sodium of coco is likely a key issue. Nothing else is actually high, by any measure, except perhaps K, which again, is coming from the coco

I'm still looking for good CoCo/LED grows. As time goes by, I become more convinced coco is out of it's depth with the speeds LEDs can promote.

I'm still on your problem being sodium and bicarbonate buildup. Coir retains sodium and k in quantity. When sodium + k is greater than 10% of the bases it can create al,fe toxicities accompanied by mn issues. Also,as a mix breaks down the more bicarbonates it has which brings its own issues. In this situation I had better growth with equal ppm npk using mkp,c/n and with just enough map to bring up the P. Adjust mgsu as you see fit. In between feedings water frequently and thoroughly with 2-3g/gal gypsum to move the bases closer to where they need to be.

 

[f-e]

My guess is micros. Correct me if I'm wrong but that leaf looks like new growth?
If you're fine on Ca and Mg then my brain goes to some combo of micros. Do you have any pics of this issue on the plant (no plucked leaf/as is?)

They are fully formed middle leafs, that grew alright, but are now going downhill. Only when this advanced will the problem move up, but the plants are down before the very top leaves get this bad.

 

[f-e]

I'm still on your problem being sodium and bicarbonate buildup. Coir retains sodium and k in quantity. When sodium + k is greater than 10% of the bases it can create al,fe toxicities accompanied by mn issues. Also,as a mix breaks down the more bicarbonates it has which brings its own issues. In this situation I had better growth with equal ppm npk using mkp,c/n and with just enough map to bring up the P. Adjust mgsu as you see fit. In between feedings water frequently and thoroughly with 2-3g/gal gypsum to move the bases closer to where they need to be.

I have not updated my old thread, but will very soon. I have got past the buggered leaves, that seems to of been oxygen deprived due to competition. The browning off is the same though, to the day, no matter how I feed. Looking at other people diaries, It's not just me, but my progression is quicker. Burning hairs often speeded along by a dry down. As is this problem. I'm using RO now so bicarbonates are much less likely to be the problem, but I'm still in coco.

Very interesting about the 10% as I can't actually get them below 10%. If I feed high enough, my rapid dry back causes large EC swings that they can't be expected to tolerate. The canna coco is making about 90ppm of K in my runoff, a few times a day. So there is a 1000ppm requirement straight away. However my food, in any quantity, is also over 10%, as is any. This is just looking at K alone. So to get under 10% I would have to mix my own, with no K. Which nobody does. The equal npk example appears to get nowhere near just 10% though, so perhaps I'm just too tired to hear you properly

 

[jackspratt61]

I have not updated my old thread, but will very soon. I have got past the buggered leaves, that seems to of been oxygen deprived due to competition. The browning off is the same though, to the day, no matter how I feed. Looking at other people diaries, It's not just me, but my progression is quicker. Burning hairs often speeded along by a dry down. As is this problem. I'm using RO now so bicarbonates are much less likely to be the problem, but I'm still in coco.

Very interesting about the 10% as I can't actually get them below 10%. If I feed high enough, my rapid dry back causes large EC swings that they can't be expected to tolerate. The canna coco is making about 90ppm of K in my runoff, a few times a day. So there is a 1000ppm requirement straight away. However my food, in any quantity, is also over 10%, as is any. This is just looking at K alone. So to get under 10% I would have to mix my own, with no K. Which nobody does. The equal npk example appears to get nowhere near just 10% though, so perhaps I'm just too tired to hear you properly

The 10% is a measurement of the base saturations in your substrate.,not the feed. The dry downs are not good in these conditions. Continuously running gypsum in measured amounts to control bicarbonates and sodium from overloading works. In Benton Jones jr. book Complete Guide to Hydrponics there is a graph of the equilibrium of coir when exposed to a nutrient solution. A 15 ppm Na feed reached equilibrium at 225ppm in the media.

 

[tobedetermined]

Now, I am just a new grower with a little over a dozen grows under my belt and you guys are discussing shit above my pay grade but . . .

Why not stop the ferts you are using & go back to basics? A pre-made store bought solution. Get back to having some successful grows again. I grow in coco/perlite. I have only ever used LED lights. And I have never had the problem you have pictured.