Mg??

[f-e]

tobedetermined I'm using store bought. The only addition is calmag, as I have moved to RO water. I have used a couple of brands recently. One was better but the listing on the bottle was total bollox, so taught me nothing. Except to avoid GH.


jackspratt61 That's interesting. I should of realised. Unfortunately I don't have a lab that can look at coco, which ties my hands somewhat. I'm not sure where such salt levels would come from though, if not the coco itself. I'm using very common supplies really.


My change of feed is inconclusive, but telling. In a 24 hour period the hairs on one strain went from 50% brown to over 80% brown. They sure hated it. Resin pumped out at the same time though, so they went from almost ready to done, very quickly indeed. Though this isn't that uncommon around day 34. The only thing I have ever seen related to premature aging is Mg, the obvious reason for such stripes. The stripes didn't spread, but do seem to of got more vibrant in places. The only certainty is calcium signs appeared. Along with some edges going in a manner similar to what I thought I had seen the back of. I was at half feed though, with the trace stuff at about 120%. Not a great test, but the hairs going brown so rapidly shows it's not caused by excess NPK Ca or Mg. Which is good to know as an over feed was always most likely. I have something in the trace to blame. Something the Ca probably holds back. Something likely more prevalent in my feed than the GH, but again, the GH label is nonsense they tell me, so of no diagnostic value.

I reckon it is sodium. I dropped the K Mg and Ca, and got burnt hairs and some edges go like only sodium and chlorides are usually associated with. What's most odd though, is how its gone downhill over a few years. I can repeat earlier grows exactly, and get ill plants and half the yield. I'm pretty sure this isn't something I'm doing, after 30 years.

If I get off my arse I can do a run with canna terra. A weak compost like stuff that you run like hydro.
I wouldn't know where to start with adding gypsum. However I moved from tap because it's bore hole water from a gypsum mining area. I have 175ppm CaCO3 of a total 225ppm expressed as CaCO3. I'm hoping to start using it again. The RO is just a temporary measure as I try everything.

 

[jackspratt61]

tobedetermined I'm using store bought. The only addition is calmag, as I have moved to RO water. I have used a couple of brands recently. One was better but the listing on the bottle was total bollox, so taught me nothing. Except to avoid GH.


jackspratt61 That's interesting. I should of realised. Unfortunately I don't have a lab that can look at coco, which ties my hands somewhat. I'm not sure where such salt levels would come from though, if not the coco itself. I'm using very common supplies really.


My change of feed is inconclusive, but telling. In a 24 hour period the hairs on one strain went from 50% brown to over 80% brown. They sure hated it. Resin pumped out at the same time though, so they went from almost ready to done, very quickly indeed. Though this isn't that uncommon around day 34. The only thing I have ever seen related to premature aging is Mg, the obvious reason for such stripes. The stripes didn't spread, but do seem to of got more vibrant in places. The only certainty is calcium signs appeared. Along with some edges going in a manner similar to what I thought I had seen the back of. I was at half feed though, with the trace stuff at about 120%. Not a great test, but the hairs going brown so rapidly shows it's not caused by excess NPK Ca or Mg. Which is good to know as an over feed was always most likely. I have something in the trace to blame. Something the Ca probably holds back. Something likely more prevalent in my feed than the GH, but again, the GH label is nonsense they tell me, so of no diagnostic value.

I reckon it is sodium. I dropped the K Mg and Ca, and got burnt hairs and some edges go like only sodium and chlorides are usually associated with. What's most odd though, is how its gone downhill over a few years. I can repeat earlier grows exactly, and get ill plants and half the yield. I'm pretty sure this isn't something I'm doing, after 30 years.

If I get off my arse I can do a run with canna terra. A weak compost like stuff that you run like hydro.
I wouldn't know where to start with adding gypsum. However I moved from tap because it's bore hole water from a gypsum mining area. I have 175ppm CaCO3 of a total 225ppm expressed as CaCO3. I'm hoping to start using it again. The RO is just a temporary measure as I try everything.

An interesting exercise is to use your feed in 100% perlite to eliminate the medium interactions. Alot can be learned with one plant.

 

[Switcher56]

*1

 

[f-e]

I just did a 50% (by volume) run. I got the same premature aging and some stripes. GH feed though. I found on that run that halving their idea of a weak feed from 4 weeks of bloom was useful. While slamming up the light and foliar feeding Mg. Good for perlite, anyway. The bottom inch of my pots are 50/50 right now, but the rest 100% coco.


If I search Mg deficiency cannabis, The full range of pics associated with that term, pretty much cover all the main and random signs I see. I just can't put enough in though. I think I need to load up, then apply a maintenance dose. Which I can't judge.

I'm going to look up 'ashing' and see why I have not done that already. It's basically taking all my leaves off and putting them in Nitric. You filter the mush and the acid then contains all the leaf except.. I dunno really. Then you boil off the Nitric with distilled water. I think that might be a fume cupboard job. It's the fluid left that I can get analysed. To et a leaf tissue analysis done, without leaf.

 

[GoatCheese]

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.

Hey, f-e..

You wrote that the yellowing gets worse when the coco dries out more?

To me that leaf in the photo has that dry-look that is caused by LED lights running abit too hot/too close to canopy = the leaf loses it’s waxy shine and starts to feel abit dry in your fingers.
If your coco dries out several times a week abit too much when the lights are still on, eventually you will see yellowing leaves and the first signs of LED radiation damage; dried out look – leaves starting to loose their waxy shine.

Like negative37dBA replied earlier, maybe you need to dim the leds down abit or raise them higher.
What kind of watts you’re running with your leds? How much distance to canopy?

Maybe you still remember me telling you some months ago that you're running your LEDs abit too hot!!??

 

[f-e]

Hey GC, where you been
I'm running the lights lower, but the net result is lower yield. Just over 300w per meter the last few, as I cycle around the possibilities. Last run I decided I wanted some yield though and went 450w half way through, which they liked. That's pretty much historic fact. They like 450w a meter and at 500w they are unhappy. That 330w at the wall is ~600ppfd so I'm seeing improvements to 1000 then issues. Which aligns with written articles. I'm not willing to drop below 600ppfd as going higher has always bought improvement. Plus not achieving 600 is itself a failure.

The advance when they didn't get fed is awkward data. A dry back should help Iron, which is often shown as stripes like mine. However root EC will of peaked, and fluid movement slowed. There is a lot going on to learn anything from it as a single piece of the larger puzzle.

I have got a pic of what I called Calcium signs, running the low feed with high trace. As I'm not willing to commit to the fact it's calcium (based on the wide range of published deficiency pics, some of which are blatantly wrong). You can see low on the plant, how the stripes start is a whitening more than the later yellowing. During transition when Ca and Mg seem more important, these lighter stripes sometimes get a rash or necrosis. Bit rusty looking which I believe is Calcium. It's into bloom the rashing won't come, but instead the stripes progress to yellow. I think it's possible that the problem actually shifted from calcium stripes and spotting, to magnesium stripes. I would love to get tissue samples done. My entire crop isn't big enough to provide the number of leaves required though, if anywhere did it. There are no test's for small sample sizes. Though the actual requirement is hazy.

The stripes below. Some Mg looking serrations. Then after a quick starve, a leaf lightening off somewhat, but what I'm looking at, the tip and edges.
Is it just cal and mag? The pH swung up without the calmag, which I found odd.

I also got a leaf do something reminiscent of my last problem thread, which I thought was behind me. Only a small part of all that though..(I have been on this thread over an hour trying to upload with my weak connection)

Shitty little bud that should never be on top... 5 weeks.

 

[f-e]

Interesting... closest I can find to my suspected Ca... is burn

Not just close, Identical. On my lowest feed days, but with slightly elevated trace mix. Suggesting, quite firmly, that I have toxicity where I have not been looking. Hmm.
Edit: I fancy the idea that the Sodium and Potassium gained to much ground, when the calmag was pulled. I must look at the Trace option though

 

[GoatCheese]

Interesting... closest I can find to my suspected Ca... is burn

Not just close, Identical. On my lowest feed days, but with slightly elevated trace mix. Suggesting, quite firmly, that I have toxicity where I have not been looking. Hmm.
Edit: I fancy the idea that the Sodium and Potassium gained to much ground, when the calmag was pulled. I must look at the Trace option though

That’s defo caused by LED-radiation and the coco drying out too much.
If you feel you don’t want to dim the lights down, then i suggest that you don’t allow the coco to dry out so much any more. = re-think your watering schedule abit
-
-
About the yellowy stripes, imo that is caused by the grow medium drying out too much and the plant starting to use the moisture in it’s leaves ...i don’t think it’s a sign of deficiency of any kind, but drying out damage.
The yellowing caused by the medium drying out too badly doesn’t always show just on the tops closest to the lights, but cannabis seems to be a clever plant and many times they start to drop/dry out leaves that are in the shade ..meaning it seems cannabis can sense what leaves they don’t need any more that badly and start withdrawing moisture/nutrients out of those leaves.

 

[exploziv]

In my grows i have seen Ca, Mg and rarely P deffs. It is only seen under high intensity leds, basically I seen this only since switching to Mars Hydro leds. My soil used to keep a plant happy for a whole grow. Now i need like double doses of nutes with high cal mag content to keep them happy. It's crazy.

 

[GoatCheese]

In my grows i have seen Ca, Mg and rarely P deffs. It is only seen under high intensity leds, basically I seen this only since switching to Mars Hydro leds. My soil used to keep a plant happy for a whole grow. Now i need like double doses of nutes with high cal mag content to keep them happy. It's crazy.

Now that i’ve changed to COBs/LEDs I still use the same nutrient strength as i did when i used a 400/250w hps lights. My NPK nutrient strength is exactly the same, the only thing i have added is calmag (0,3ml/L) and epsom salts once a month.

I bet you’d see the problem go away if you’d just raise the light fixture higher or dim it down abit if you can’t raise it any higher.
The yellowing/pale color is caused by the LED radiation heating the leaf (leaf surface temperature) which then dehydrates it causing the leaf to turn yellow/pale colored, it’s not a nutrient deficiency of any kind, imo.

Most modern high powered LED lights need at least 60-70cm distance to canopy or even more. If you can’t manage that in your grow area, tent or a low ceiling space, then you just have to dim the light down abit. When you have enough distance between the LEDs and the canopy you will notice they don't need any extra nutes under LEDs compared to HPS lights.

 

[exploziv]

Thank you, lights are pretty dimmed right now and I can still see problems. Will try to raise them a bit, but I suspect with lights at 25% and 30 cm away that is not the problem. Used burple leds before and I had no dimmer in those, had no problems.
Its very weird and I used a lot of things hoping to see a change, and nothing seems to fix it other than crazy ammounts of ca and mg.

 

[f-e]

Hey GC. The image you have quoted is from our infirmary. It's over feed. Generally to much salt, though not specifically sodium. However sodium toxicity does look very similar when seen in other plants. Finding pics in canna has proved difficult. Plants are not particularly good at blocking sodium uptake. Coconut trees have just learn to live with it. Sodium can take the place of K in many plant species, as much as 80%. Causing a softening of fruits. We have to suppress it's competition with the K,Ca,Mg triangle, by keeping their levels high. My problem is starting to look like a combination of small pots and salty coco. Small pots give a rapid dry down, which causes rapid EC changes. Not especially dry (unless like this time, I messed up) but still a fair swing. My EC is about 0.7 in order to keep the upward swing in check. It's perhaps not enough to suppress the Sodium. I'm stuck with the coco giving out sodium and potassium, while I must balance up the Ca and Mg needs. My Ca is very low, and still I can't get enough Mg in there. The total feed concentration becomes too high and they don't take it. What I can do is run very low EC, while banging up the lights to get it moving through the plants. Spraying Mg on them. It's a full time job balancing it all though. I have quite a bit of root compared to coco, which is physically braking it up releasing this toxic sodium that coconuts have learned to live with, but canna hasn't.

I do wonder why this has been getting more problematic. Over the years I have had good and bad bags of canna coco, and heard the excuses why. Look at the worldwide trade of coco, demand must of soared with legalisation in many states. There is pressure on the supply chain to get it rotted down, and out the pits, as quick as possible. There is a parallel time line between my problems and legalisation. I have to wonder.

One thing stands out. My browning hairs problem comes on the same day almost every time. When demand for flower food increases, I'm lowering my EC as my over feed like issue are coming on strong. It stands to reason they are looking for K and sucking up sodium. A refusal to eat comes hand in hand. I think others are able to bang up the feed to suppressing levels. While my faster dry back stops me.


I don't want to talk about my other thread here, but when I tried larger containers and many waterings per day, my water was as 'flat' as last years lemonade. I had a fungus problem in the tank that was sucking all the oxygen out. I had to culture the stuff to see it. I was using a black feed and putting in so many seaweed products and microlife, I had mistaken what I was seeing. I have the pump that works with H2O2 now, and remember that coco isn't meant to smell a bit like soil. Damn creeping problems.. But that seems to of been the odd leaf patterning and mild lower wilting. The brown hairs are still with me. Along with the stripes. Which I'm looking at sodium for.

Another forum uses this pic as it's main cover image for the deficiency section. Later it appears in the Mg section.


I am quite convinced it's Mg, but I just can't get enough in, as my total salts get silly. I was interested in peoples opinions if Mg was taken away as an option, but I just can't get away from it being Mg when I put the ideas together with the full knowledge I have of my problem (which the people offering advice won't know all of). My K Ca Mg triangle is saturated by sodium and potasium from the coco, before I get to add the Ca and Mg requirements of this LED grow.

Or I could be wrong. It's certainly open for debate

My feed of choice has always been Ionic. I switch to others, but always come back. The coco feed, by listing, is just 50ppm Ca and while Mg is listed as present, no value is given. I don't think any list Mg quantities. So it's traditionally the issue I see, as I guess we are meant to use our own, dependent on our grows/taps. It works in bigger buckets where their is a greater volume of everything. I reckon my life long mission to use tiny pots has found a limit though. It's a shame, 1L of coco supported 4.5oz plants using just ionic a few years ago. Now I'm lucky to get 2oz with no real changes. The plants refuse to eat from week 3 of bloom, and by day 24 hairs are burning. 10 days later, some strains are fried. The advance of browning increasing every day. Regardless of how I feed.

 

[GoatCheese]

Thank you, lights are pretty dimmed right now and I can still see problems. Will try to raise them a bit, but I suspect with lights at 25% and 30 cm away that is not the problem. Used burple leds before and I had no dimmer in those, had no problems.
Its very weird and I used a lot of things hoping to see a change, and nothing seems to fix it other than crazy ammounts of ca and mg.

I noticed that it’s better to keep the lights hanging high and use more watts than keeping the lights very close to canopy and using less watts.
At first i also used my cobs/leds quite close to canopy around 30-40cm but i got the yellowing happening very easily. Then i raised my cobs to hang about 75cm above canopy and noticed i could use much, much more light without the plants getting damaged
...meaning, the so called “inverse square law” of light intensity doesn’t seemingly work with modern LEDs and cannabis growing = once you have the LEDs raised high enough, you can have more lumens on canopy level without the plants getting damaged, compared to if you have the LEDs very close to canopy and you try to dim the light down to suit your plants.

As an example, if you want to achieve 700 ppfd on canopy level, it’s better to raise the LEDs quite high (75cm+) above canopy and to use more watts to get to that level, than trying to achieve that 700 ppfd level by having the LEDs very close to canopy (30-40cm)

Do you understand what i’m trying to say with this? English isn’t my first language so i’m struggling abit to find the right words to explain this any better.

 

[GoatCheese]

Hey GC. The image you have quoted is from our infirmary. It's over feed. Generally to much salt, though not specifically sodium. However sodium toxicity does look very similar when seen in other plants. Finding pics in canna has proved difficult. Plants are not particularly good at blocking sodium uptake. Coconut trees have just learn to live with it. Sodium can take the place of K in many plant species, as much as 80%. Causing a softening of fruits. We have to suppress it's competition with the K,Ca,Mg triangle, by keeping their levels high. My problem is starting to look like a combination of small pots and salty coco. Small pots give a rapid dry down, which causes rapid EC changes. Not especially dry (unless like this time, I messed up) but still a fair swing. My EC is about 0.7 in order to keep the upward swing in check. It's perhaps not enough to suppress the Sodium. I'm stuck with the coco giving out sodium and potassium, while I must balance up the Ca and Mg needs. My Ca is very low, and still I can't get enough Mg in there. The total feed concentration becomes too high and they don't take it. What I can do is run very low EC, while banging up the lights to get it moving through the plants. Spraying Mg on them. It's a full time job balancing it all though. I have quite a bit of root compared to coco, which is physically braking it up releasing this toxic sodium that coconuts have learned to live with, but canna hasn't.

I do wonder why this has been getting more problematic. Over the years I have had good and bad bags of canna coco, and heard the excuses why. Look at the worldwide trade of coco, demand must of soared with legalisation in many states. There is pressure on the supply chain to get it rotted down, and out the pits, as quick as possible. There is a parallel time line between my problems and legalisation. I have to wonder.

One thing stands out. My browning hairs problem comes on the same day almost every time. When demand for flower food increases, I'm lowering my EC as my over feed like issue are coming on strong. It stands to reason they are looking for K and sucking up sodium. A refusal to eat comes hand in hand. I think others are able to bang up the feed to suppressing levels. While my faster dry back stops me.


I don't want to talk about my other thread here, but when I tried larger containers and many waterings per day, my water was as 'flat' as last years lemonade. I had a fungus problem in the tank that was sucking all the oxygen out. I had to culture the stuff to see it. I was using a black feed and putting in so many seaweed products and microlife, I had mistaken what I was seeing. I have the pump that works with H2O2 now, and remember that coco isn't meant to smell a bit like soil. Damn creeping problems.. But that seems to of been the odd leaf patterning and mild lower wilting. The brown hairs are still with me. Along with the stripes. Which I'm looking at sodium for.

Another forum uses this pic as it's main cover image for the deficiency section. Later it appears in the Mg section.
filedata/fetch?id=17942030&d=1631545826

I am quite convinced it's Mg, but I just can't get enough in, as my total salts get silly. I was interested in peoples opinions if Mg was taken away as an option, but I just can't get away from it being Mg when I put the ideas together with the full knowledge I have of my problem (which the people offering advice won't know all of). My K Ca Mg triangle is saturated by sodium and potasium from the coco, before I get to add the Ca and Mg requirements of this LED grow.

Or I could be wrong. It's certainly open for debate

My feed of choice has always been Ionic. I switch to others, but always come back. The coco feed, by listing, is just 50ppm Ca and while Mg is listed as present, no value is given. I don't think any list Mg quantities. So it's traditionally the issue I see, as I guess we are meant to use our own, dependent on our grows/taps. It works in bigger buckets where their is a greater volume of everything. I reckon my life long mission to use tiny pots has found a limit though. It's a shame, 1L of coco supported 4.5oz plants using just ionic a few years ago. Now I'm lucky to get 2oz with no real changes. The plants refuse to eat from week 3 of bloom, and by day 24 hairs are burning. 10 days later, some strains are fried. The advance of browning increasing every day. Regardless of how I feed.

OK so the picture i commented on wasn’t one of your plants? Maybe you should just show photos of your plants so we could actually see whats going on..

Anyways, the damage on the plant in the photo i commented on(post # 27) was caused by light intensity (upwards tacoing and yellowing leaves), that is not what over feeding looks like = the yellowing/taco is happening only on the other side of the top (assuming the light side) but on the other side of the top the leaves seem to look greener. If that would be nute burn-yellowing the tops would look yellow/burned on both sides


LED dehydrated leaves can develop brown, nute burn like spots if the plant was being fed heavily when it dried out and the yellowing happened, because the EC level of the moisture in the plant tissue rises when the water evaporates away ...so that’s why the LED radiation damage can look abit like nute burn, but the real cause of this is the leaf getting dehydrated because of LED radiation intensity.

 

[exploziv]

I noticed that it’s better to keep the lights hanging high and use more watts than keeping the lights very close to canopy and using less watts.
At first i also used my cobs/leds quite close to canopy around 30-40cm but i got the yellowing happening very easily. Then i raised my cobs to hang about 75cm above canopy and noticed i could use much, much more light without the plants getting damaged
...meaning, the so called “inverse square law” of light intensity doesn’t seemingly work with modern LEDs and cannabis growing = once you have the LEDs raised high enough, you can have more lumens on canopy level without the plants getting damaged, compared to if you have the LEDs very close to canopy and you try to dim the light down to suit your plants.

As an example, if you want to achieve 700 ppfd on canopy level, it’s better to raise the LEDs quite high (75cm+) above canopy and to use more watts to get to that level, than trying to achieve that 700 ppfd level by having the LEDs very close to canopy (30-40cm)

Do you understand what i’m trying to say with this? English isn’t my first language so i’m struggling abit to find the right words to explain this any better.

Yeah man, it is pretty clear. Thank you. Will do a test with it further away and with more power from the dimmer for a while, see how it goes.

 

[f-e]

OK so the picture i commented on wasn’t one of your plants? Maybe you should just show photos of your plants so we could actually see whats going on..

Anyways, the damage on the plant in the photo i commented on(post # 27) was caused by light intensity (upwards tacoing and yellowing leaves), that is not what over feeding looks like = the yellowing/taco is happening only on the other side of the top (assuming the light side) but on the other side of the top the leaves seem to look greener. If that would be nute burn-yellowing the tops would look yellow/burned on both sides


LED dehydrated leaves can develop brown, nute burn like spots if the plant was being fed heavily when it dried out and the yellowing happened, because the EC level of the moisture in the plant tissue rises when the water evaporates away ...so that’s why the LED radiation damage can look abit like nute burn, but the real cause of this is the leaf getting dehydrated because of LED radiation intensity.

This pic?


That's from our infirmary, used as over feed. It's probably in soil with too much K, as it's burning them and suppressing Mg. The pic is much older than LED use. It's not just scorched at the top. It's all over.
I see strong parallels to light burn though. I just bumped a thread on such issues. Talking about if K might be the problem. I didn't say there, but we keep adding more Ca, but excess Ca helps K along, rather than competes with it.

I'm off to buy some soil lol

 

[GoatCheese]

Even if that photo was taken of a HPS grown plant, the damage was still mainly caused by heat radiation, that’s not normal nute burn, imo; the leaves in the front are more dried out/yellow than the leaves on the other side of the top (thou you can see only few of them), which to me says the more damaged side was facing the light source. Also the lower you go the greener the leaves are.
..if you look at the lower leaves on that photo that aren’t so damaged, there’s hardly even tip burn from too heavy feeding, so i doubt too heavy feeding was the main issue with that plant. Sure there is nute burn damage there but imo it was caused by the plant drying out

HPS heat damage or LED radiation damage are essentially the same thing, in which the leaf has dehydrated because of radiation. ..and why it looks like a nute burn with the brown spots is because the EC value in the plant tissue went up when the moisture started evaporating off the leaf.
But enough of that old photo, it's not important.

-
-
Yea, soil is quite easy grow medium once you get the watering cycle right, not over or under watering your plants. No need for EC or pH meters if you live in an area with good and stable tap water. I haven’t measured the pH of my tap water in a decade or more but we have fairly stable water over here.

Plants can yield quite well in soil too but you just have to veg them longer/larger before you start flowering them, cause the growth is slower than with hydro growing.

For soil growing, i recommend you look into organic nutrients. With mineral nutes you have to worry about salt build up in soil; give them a proper flush few times a month, that is. organic stuff is quite care free once you find the proper nute strength for your plants.

Sorry, i can’t tell you what are the best organic nutes for cannabis growing. I use BioBizz nutes, as you know, but i use them mainly cause they are fairly cheap (high concentration) not because i’d know they are better nutes than some other line. BioBizz aren’t cannabis specific nutes and they give you abit too much Nitrogen for later half of bloom, so i have started replacing some of the Grow-component with PK13/14 to lower the N levels during the last few weeks that i give my plants nutrients. But too much Nitrogen for flowering stages is a problem with other nute lines also, not just BioBizz, imo.