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LED feed demands

GoatCheese

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So I have P, Ca, Mg deffs. Distance from leds or leds intensity doesnt change much of it. Feeding double full doses of nutes almost every watering seems to fix it for a while, unless 3 times max dose is what they need. But then N is through the roof, as i use organics and almost all of them have some N.
I am bummed. What can I do to improve my situation? I plan on starting fresh with simpler soil mix snd simpler feed regimen trying to figure it out as I go. What would you guys do?

When you have had proper LED yellowing going on, it won’t fix itself very well, esp. in soil. Only the new growth will have normal color once you have managed to dial in the LEDs, but the older growth will stay pale for a good while...esp. when the lights are dialed in just below the limit that they can take.

So if you try different hanging heights for the LEDs, you won’t see much improvement in a day or two. The only way i “feel” improvement in a day or two is that the leaf tissue becomes softer(more moist) in my fingers, but they still look about just as shitty as when the lights were hanging abit too close to them.
..the little improvement you can see in a day when you’ve found the right height for the amount of watts you're using is that the leaves will point upwards abit more normally ..when my LEDs are abit too close to the plants (or are running with too much watts) the leaves on the tops start to point down wards abit; how much depends how much over the top the light was for them
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One thing you have to do differently with LEDs compared to growing under HPS lights is that you can’t let the soil dry out as much under modern LEDs. So you have to pay more attention to right kind of watering cycle

And like F-E, i have more leaf yellowing problems when i’m growing in smaller containers, cause the soil dries out faster if i don’t get the watering cycle just right..i don’t even see the leaves drooping at all from the soil drying out when i already get leaf yellowing under LEDs/COBs. with hps light the leaves could have a proper drooping and still you didn’t see much yellowing on the leaves, esp. if the hps was cool tubed.
 

GoatCheese

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Supplemental IR and UV chips..

I see people with IR and UV chips on their plug-n-play LED lights, like some Mars Hydro models, also having yellowing problems, not just people like me who are growing only with the basic LED/COB arrangements. I’m not saying these supplemental chips aren’t helping at all, i really don’t know personally, just saying i don’t think they will solve the whole issue.
But yes it would be cool to see side by side comparison grow with IR (and UV) chips vs. without.
 

f-e

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Supplemental IR and UV chips..

I see people with IR and UV chips on their plug-n-play LED lights, like some Mars Hydro models, also having yellowing problems, not just people like me who are growing only with the basic LED/COB arrangements. I’m not saying these supplemental chips aren’t helping at all, i really don’t know personally, just saying i don’t think they will solve the whole issue.
But yes it would be cool to see side by side comparison grow with IR (and UV) chips vs. without.

Thank's GC. I have not been following the lights people are using.
It's worth consideration, that the amount of IR we do add with LED's, is almost nothing. We concentrate on things like the 730nm that show results in plant weight terms. However that's not what I'm getting at. A HID might turn 12% of it's power into light, and double that into radiant heat. The stuff that influences the stomata.

I must spend some time looking at the stomata at a higher level than my typical daily state allows. There will be a number of reasons behind their action. GC, have you tried a higher RH? Your room is very dry. This leads to water preservation actions. Closing of the stomata. If this was the main controlling influence over stomata size in your room, there would be a set of issues attached to this. One is the intake of co2 which is I have seen mapped out in leaf tissue against illumination. Spoke of as the limit to light input. With detailed descriptions of how the plants act as light goes higher and higher above ideal levels. CO2 users must run higher RH with their higher lighting, to open the plants up to it. How IR quite fits, I'm unsure. I have two conflicting ideas. 1, the plants hot so must sweat. 2, the plant must conserve water. Your thoughts on not getting to dry at the root, are keeping the stomata from closing further. When you start adding it all up, there is a case for running higher RH and wetter feet, to open them up to co2, in order to use higher light.

My last run, I was going dry twice a day in coco. Intuition tells me that sopping wet coco wasn't for me. The plants liked it. I think I'm generally running too wet and too high an RH as my venting is challenged. It was constantly areas of my grow going wrong, rather than plant types. Some were certainly more sensitive, but the areas getting a greater share of recycled air were worst, where that odd leaf patterning showed.

I have noticed that using my calmag brings about calcium signs at the tips. Signs usually seen in wheat. Slightly small growing tips that are light in colour and don't want to open up. It's probably the N quota getting involved with the ion exchange that moves calcium. I'm not sure of the N type though. Only the more organic version can do this. Perhaps I should keep this to myself.. It's not for this thread unless others see it.

Part of my move to soil is to get a better supply of Ca and Mg, without the K. I couldn't push the K out with Ca, as Mg was already suffering. The K Ca Mg quota was taken up by the coco's K and sodium. I was having to drop Ca to get in Mg. My quick dry down times were surely a big part of why the total salts was too high. I just couldn't get any lower though. I had to combat the cocos excessive output.

So far, I have used calmag twice, as I felt I should. No signs. I just felt it a good idea. Both times they looked bad afterwards. So I'm on straight food that only lists npk. I have reached bottle dose, which was nerve racking, but is the best they have looked on this run. Just under 450w at maybe 300mm. I lost one to over watering. I could see it coming but I don't have taps for individual pots. It might of had a root problem. It certainly does now. Not lost one in many years, but I let it go as a move to soil long term, means it's not a suitable strain perhaps. It's sibling is also meh. Generally looks alright though, and you know I'm the first to say my crops shit.
 

Greenheart

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Given that Mg seems a common deficiency and that Epsom Salts seem to be one of the more applied and successful remedies in this thread what are you thoughts on Sulfur? I was reading this article that got me thinking about it. A lot of things said in this thread about nutrient interactions made a bit more sense to me after reading it.
 

GoatCheese

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GC, have you tried a higher RH? Your room is very dry.

Yea, i have noticed that during summers when there’s higher humidity % i can push my LEDs/COBs more than during winters without my plants looking so bad.
I can get the humidity in my veg cabs to rise past 80% even during winters quite easily by keeping the door shut, but still i have to be very careful with the COB and Samsungs, and the watering cycle, or i will start seeing yellowing.

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About fans and ventilation, esp. during low humidity seasons my plants that are in the direction where the fan is blowing air they get noticeably more dehydrated and get the yellowing going much easier than the plants in the other side of the tent/cab.
..also, the plants that are closer to the door in my veg cab during winters, when i keep it ajar at times, look worse/drier than the plants that are further back.

It all points to dehydration problem, why the leaves start looking so bad under LEDs.

Before i read about calmag and epsoms helping plants stay in better shape under leds, growing during winter was a big problem for me. Winters were a problem even during the hps days but when i changed to COBs, forget about it...



I’m not very savy when it gets to botany talk, plant biology and what ever. Haven’t looked much into it at all, cause I’m not so into the actual growing part of my cannabis hobby. I like smoking it much, much more than growing it, and the only reason i had to get better at growing is because i have to smoke the stuff that i grow.
..but i have smoked superbly grown bud two times in my life (once in Amsterdam; UK Cheese and once in Christiania Denmark; White Widow), so i know when my growing isn’t up to par, which is the reason i started to tinker with my NPK ratios, btw. I’m still not as good as the growers that grew the superb stuff but i’m slowly getting closer.

PS.
..yea, i have smoked only one really good batch of weed in Amsterdam during the 5-6 times i have visited the place. Most times the stuff is worse than what i grow at home.:biglaugh:
 

GoatCheese

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So far, I have used calmag twice, as I felt I should. No signs. I just felt it a good idea. Both times they looked bad afterwards. So I'm on straight food that only lists npk. I have reached bottle dose, which was nerve racking, but is the best they have looked on this run.

Maybe your plants start to look worse after calmag cause you’ve been using higher EC and calmag raises it even more? I see only good signs from calmag and epsoms, so it’s abit strange it’s not working for you.
I use 0,3ml/L of Canna calmag with every nutrient feed, maybe i have to up it to 0,5ml/L during winter, lets see. I’m still experimenting with it. Epsoms once in 2-3 weeks
 

f-e

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My current feed (Plagron) is just 5ml per liter. I was at 3 when I used the calmag the first time. I flushed it away at 4ml which gave the same EC. The tops were light so I went for 5ml and they look alright. I then tried 4ml again as I moved to flower feed. Using calmag to put the N back to grow levels, it looked the same poor condition. Quite odd. I have used separate calcium and epsom and that was alright. Just the combination bottle with it's N isn't good. Two brands tried.

I just found a bad leaf at the bottom. Some N deficiency I don't mind, but one bad one. Looks a bit like Mg but not quite. I will have to let it progress. I'm not actually keeping a diary on this first soil run, I'm being sloppy and not even measuring runoff. Just learning the ropes again. New feed. New substrate. I don't know what to do with it yet. I think change feeds though, as just npk shouldn't even work in my little pots of light'ish mix.


Dehydration since moving from HID too LED.
Do they actually drink as much? I have pondered the question of surface RH verse room RH a few times. As the rooms RH comes from the leaves, it's surely higher at the leaf surface. Many fold higher. Such that if the room is just 2% drier, the effect will be many fold greater at the leaf surface. Obviously we measure the room, but it's the surface that matters.
I'm pretty sure from the smell, that my stomata open as I turn off the lights. An effect that was more noticeable with HID's, to the point where I used to know the lights had gone off, yet under LED I don't. Something I had not missed until thinking about it just now. The RH peak was quite quick on my datalogging devices, and would carry the green smell through a filter. I have to deduce the IR from the lights closes the stomata to conserve moisture. So a lack of IR might leave them open, loosing moisture. Combated with RH and water at the root. Which your findings seem to tally with.
That suggests that under LED you are actually loosing a load of moisture. Rather than the usual story of not loosing enough. I know in my early LED grows I was reaching 10L not the 6L of HID grows. Now I'm back to 6L but I'm not hitting the numbers of HID or LED, making this mute.
 

exploziv

pure dynamite
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Given that Mg seems a common deficiency and that Epsom Salts seem to be one of the more applied and successful remedies in this thread what are you thoughts on Sulfur? I was reading this article that got me thinking about it. A lot of things said in this thread about nutrient interactions made a bit more sense to me after reading it.

Sulfur overfert? I was thinking about that too some time ago, and it kinda looks like it sometimes (simar to ca spots), but then my plants looked the same before and after I started using epsom salt. Next grow I won't use it anymore, see what happens.
Will also put some pics of the plants soon. I abandoned the idea of finishing the grow but kept the plants watered and under low light to show more of their problems, maybe someone has an ideea on what happens there once I take some pics. That's kinda my last chance of figuring it out before starting new grow. See you guys with the pics soon. Thank you!
 

GoatCheese

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Dehydration since moving from HID too LED.
Do they actually drink as much? I have pondered the question of surface RH verse room RH a few times. As the rooms RH comes from the leaves, it's surely higher at the leaf surface. Many fold higher. Such that if the room is just 2% drier, the effect will be many fold greater at the leaf surface. Obviously we measure the room, but it's the surface that matters.

Yea my plants are drinking quite well. not as much as under a HPS but still quite well. Where i notice the difference the most is the soil surface doesn’t dry out as much with LEDs as it did under a hps, but i always assumed it’s because my COBs don’t warm up the tent as much and so the moisture in the soil won’t evaporate as much.

The leaves of 3 week old seedlings, i just popped a pack of MNS NL5Afghan, seem to sweat quite abit under my Samsungs. The plants are in little pots in a small cab and very close to each other and some times there’s a good amount of water droplets between the leaves when the cab door has been closed longer. I don’t have a fan in the cab, so this is easy to see.
 

GoatCheese

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Sulfur overfert? I was thinking about that too some time ago, and it kinda looks like it sometimes (simar to ca spots), but then my plants looked the same before and after I started using epsom salt. Next grow I won't use it anymore, see what happens.
Will also put some pics of the plants soon. I abandoned the idea of finishing the grow but kept the plants watered and under low light to show more of their problems, maybe someone has an ideea on what happens there once I take some pics. That's kinda my last chance of figuring it out before starting new grow. See you guys with the pics soon. Thank you!

Plants under LEDs/COBs can still flower quite well even thou the leaves look very pale, so if your grow isn’t an absolute disaster you may still get a nice harvest as long as the LEDs don’t keep stressing them out too badly and stun the growth. My first few grows under my Cree COBs, before i figured out more what’s going on and learned about calmag/epsoms, thou the plants looked like shit with alot of yellow and well fried leaves still yielded about the same as under the 250w hps light i had in the tent and when the plants looked better.
But of course if your plants are completely fucked and you’re not running out of smokes, then maybe it’s better to start over.
 

exploziv

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noexif_c45e519c.jpg
Haven't managed to get a camera in there today but i took some of the affected lower leaves. Can you guys notice anything that might help me? Will come back with pics from the plants in the following days. Today I also raised the lights from about 25 cm at about 35 to 40 cm and raised the dimmer from 25% to 50%. See if they get any better soon enaugh..
 

Chevy cHaze

Out Of Dankness Cometh Light
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Hey guys,
Hope you're all good.
These symptoms are driving me bananas... I thought I had figured it out but no! back to square one, just a bit later in flower...
I have a 120cmX120cm tent with Dosidos clones under old MH reflector units in in 15L/4gal fabric pots my organic living soilless mix with coco (LC's recipe #1, coco, perlite, worm castings amended with guanokalong complete organic mix), and also clones from the same mother in the same medium but only 8L/2gal fabric pots in a 120cmX60cm tent under two dimmable MH TS1000
I browsed through your posts and this is what I can add:
- I have no issues whatsoever under the older lights in the big tent with big pots
- I have major issues in the small tent with the small pots
- Both are flowering out with 4 weeks to go and I feed guanokalong bloom, bat boost (K2), liquid seaweed and top dress high p bat guano every other week.
- The room with both tents got really warm (28C) over the last weeks and RH is around 50%-60%.
- The plants closest to the circulating fan are more yellow than the others
- Both lights are roughly 40cm/19" above the tops

So, form my limited knowledge and subjective point of view, it's the light or the pot size.
Next I will try to leave out the K as per your thoughts, let's see.---
 

GoatCheese

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Haven't managed to get a camera in there today but i took some of the affected lower leaves. Can you guys notice anything that might help me? Will come back with pics from the plants in the following days. Today I also raised the lights from about 25 cm at about 35 to 40 cm and raised the dimmer from 25% to 50%. See if they get any better soon enaugh..

I think the brown dried out leaves (and the larger brown spots on the greener ones) have been caused by the soil drying out too much at times, at least that’s what i get when my soil dries out too much under my COBs when the lights are on the limit what the plants can take.
Same goes for the greener leaves that have started tacoing down wards from the sides – i get that too if my plants have grown abit too close to my COBs - thou part of that could be caused by too much nitrogen; those leaves look abit too green for what i would like to see on my plants, because too much N will make the bud smoke harsh.


Yea, watering cycle is abit problematic to get right in soil growing when the leds are one the limit what the plants can take; can’t let the soil dry out too much or you will get leaf yellowing, but also it is easy to over water if you water them too much.
..so it’s quite important to get the watering cycle right for each pot/strain in the grow room
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I’d say raise your lights to about 60cm. I like to have atleast 60cm for the plants that i right under my COBs and that’s during summers when the RH% is close to what it should be. During dry winters i need about 70-75cm distance to canopy right under the lights or i have to dim the COBs down abit if the plants got too tall.. Hydro/coco growers can keep their plants much closer to the lights than us soil growers can because they have more moisture in the plant tissue so the plants won’t dehydrate as easily as in soil.

Some months ago i had my G13Hz keeper growing in coco and soil right next to each other and i could keep the coco plan atleast 1/3 closer to the COBs than the one in soil. And the coco plant was right under the COBs while the one in soil was abit to the side

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Imo, no need to cull the plants if that’s the worst kind of damage you’re seeing, my plants looked way worse (much more yellowing thru out) when my COBs fried my plants during first few grows with them.

I would drop the nutrient feed to normal levels, as you’d have when you had a hps light and try to find the right hanging distance for your lights at the 50% wattage. It’s more difficult to find the right hanging height when you’re changing both; wattage and height at the same time. So leave the dimmer at 50% for now and try different hanging height for the lights.

..i would raise them to 60 cm and see how it goes for few days. If the leaves won’t start feeling softer in your fingers then maybe raise the lights another 10cm and see if that helps. But once the leaves have been fried by the leds they will feel abit harsh to the touch the reast of the grow; if they’ve developed that tacoing thing already, they won’t straighten them selves out anymore, so never mind that
 

GoatCheese

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Hey guys,
Hope you're all good.
These symptoms are driving me bananas... I thought I had figured it out but no! back to square one, just a bit later in flower...
I have a 120cmX120cm tent with Dosidos clones under old MH reflector units in in 15L/4gal fabric pots my organic living soilless mix with coco (LC's recipe #1, coco, perlite, worm castings amended with guanokalong complete organic mix), and also clones from the same mother in the same medium but only 8L/2gal fabric pots in a 120cmX60cm tent under two dimmable MH TS1000
I browsed through your posts and this is what I can add:
- I have no issues whatsoever under the older lights in the big tent with big pots
- I have major issues in the small tent with the small pots
- Both are flowering out with 4 weeks to go and I feed guanokalong bloom, bat boost (K2), liquid seaweed and top dress high p bat guano every other week.
- The room with both tents got really warm (28C) over the last weeks and RH is around 50%-60%.
- The plants closest to the circulating fan are more yellow than the others
- Both lights are roughly 40cm/19" above the tops

So, form my limited knowledge and subjective point of view, it's the light or the pot size.
Next I will try to leave out the K as per your thoughts, let's see.---

Smaller pots aren’t an issue as long as you won’t let them dry out too much, but if they dried out abit too much during lights out you have to be there watering the coco as soon as the lights turn on or you will start seeing yellowing pretty soon.

Try raising the lights to about 50-55cm. When i grew a plant in coco some months ago i couldn’t put the plant much closer to my COBs than 50 cm or i started seeing dehydration problems. that’s when the plant was directly under my COBs. Abit on the side and they have it little easier.


Yea, i have also noticed that when the lights are on the limit what the plants can take, a fan blowing on some plants will make them look worse than others.
When this gets really bad, like for me during winter when the air is very dry already, it can affect budding quite abit. I had one wide plant at the opposite side to the fan in my small tent – the fan blowing across from one corner to the opposite corner - and the half of that plant that got most of the fan air had half of the yield missing compared to the other half of the plant that wasn’t directly opposite to the fan. I never saw that when i had a hps light in there. The difference was dramatic.

So try change the fan angle abit if you can, maybe raise it a bit if you can.
 

f-e

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Smaller pots aren’t an issue as long as you won’t let them dry out too much, but if they dried out abit too much during lights out you have to be there watering the coco as soon as the lights turn on or you will start seeing yellowing pretty soon.



I also use large and small pots, where the smaller pots get problems. My last run wasn't constantly wet, and did better. Though when a real dry out came, I did suffer, as expected.

exploziv That really could be calcium. Have you tried a good dose that's not high nitrogen? In soil, I'm thinking gypsum. Needs to be Ca without N though. We have seen LED plants sucking up the N for a few users. Movement of Ca in the plant is via ion exchange where one of the N types can step in. Most issues I'm seeing could be in that group of cations.
I'm really not sure, but would go with a good hit of Ca as you are at the sacrificial point in things. Just one plant. I presume you have a few to kill off :)
 

Chevy cHaze

Out Of Dankness Cometh Light
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I'm not sure about the drying out being so much of an issue... I know not to let coco dry out, but last round I used Blumats so I could be certain to not let the coco dry out but the same thing happened.
I'm sure the lights a play a role but I always have perfectly green leaves below AND above the dying ones, so not all leaves are affected and certainly not just the top ones which are closest to the lights...
I'm thinking about doing a test with a clone in a very small pot and try all solutions discussed in veg, one at a time... if I can find the time... let's see

CC
 

GoatCheese

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I also use large and small pots, where the smaller pots get problems. My last run wasn't constantly wet, and did better. Though when a real dry out came, I did suffer, as expected.

When i was fighting thirps with a coco plant in bloom and i had to flush the coco daily so i could get some of those fuckers out of the pots that way, i noticed it is possible to over water coco also – it was straight coco no perlite or anything else in it - so maybe part of the yellowing you saw was from over watering, cause you did better when the coco wasn’t that moist all the time?

Over watering damage can be very similar looking as LED yellowing when it not so bad yet that the plant would start dropping leaves because of root damage. There’s yellowing and leaf necrosis(brown spots/ brown leaf tips) with over watering
 

GoatCheese

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I'm not sure about the drying out being so much of an issue... I know not to let coco dry out, but last round I used Blumats so I could be certain to not let the coco dry out but the same thing happened.
I'm sure the lights a play a role but I always have perfectly green leaves below AND above the dying ones, so not all leaves are affected and certainly not just the top ones which are closest to the lights...
I'm thinking about doing a test with a clone in a very small pot and try all solutions discussed in veg, one at a time... if I can find the time... let's see

CC

Few photos would help.
Are the damaged leaves getting light or are they in the shade/not facing the light source?

Cannabis seems to be a clever plant. When soil has dried just a little too much for me – not a proper dry out, just abit – i’ve seen cannabis drawing moisture out of leaves that aren’t getting that much light and/or are against my tent walls.

This has also happened when i have bent sun leaves away from the light towards the back so that growth below them could get more light and then when i have missed the watering few times within a week, the plant may have started to turn one/some of those leaves yellow as if it would feel it’s not getting much out of that leaf anymore. This doesn’t happen every time i do that.
 

Greenheart

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exploziv I was thinking too little. What if they are craving Ca, Mg, and S in higher amounts. Making the Epsom so effective since a lot of us already have high Ca from Oyster shell, Dolemite, Gypsum, Bone Meal and the like.

"Sulfur is also important in photosynthesis and crop winter hardiness."

"sulfur deficiency and nitrogen deficiency are often easily confused. Symptoms of both deficiencies may appear as stunted plants, with a general yellowing of leaves. Sulfur is immobile within the plant and does not readily move from old to new growth. With sulfur deficiency, yellowing symptoms often first appear in younger leaves, whereas with nitrogen deficiency, the yellowing appears on the older leaves first"

"Crops such as hybrid bermudagrass, alfalfa and corn that have a high dry- matter production generally require the greatest amount of sulfur. Also, potatoes and many other vegetables require large amounts of S"

From the link I shared.

Some things that got me thinking about it were:

Led is a colder environment if not supplemented

Yellowing can occur in seedling stage on the first set of leaves.


Now I can admit I likely had some poor ratios in my bed from the gate having not measured anything and dumping in the old stock all willy nilly. Even the prebagged seed starter saw issues when I kept the lights at the manufacturer's suggested height.

It also couldn't have been too bad if 1 of them didn't express issues except at the tops when they grew up into the light. It went away after trimming him. The worms survived it as well. Having thought about it in hindsight I was N, K, and Ca heavy with low P. I put a large variety of stuff in and at some pretty high amounts. Redressing with the Calphos, Magnesium Oxide, and Epsom Salts has really helped start the regreening. I'm definitely getting a lot of dark green from the heavy N but it's in veg so no worry on that. I've literally put a couple pounds of Epsom Salts in my 2'x4' bed the past few weeks. That helped but didn't eliminate.

I then raised the light and moved it to the side. It's 3 feet or more above them.

Next I've foliar fed with Molasses & Epsom

Finally I've admitted that 65f is too low. I put in 75 watts of incandescent for the heat value and choked the fan down to receive a 5 degree boost. They seemed to have liked it so far today.

The only real issues I've seen in my grow can all be accounted for with similar tales in this thread from seasoned growers who switched. I may have been a few years out of the game but I don't think it was all in my soil. I think it had a lot to do with the learning curve.

Thanks for the thread fe, & thanks to Ozz.

Cheers to the fun of crackin' the code!
 

exploziv

pure dynamite
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They did look much better when I used a very concentrated (30% available Ca) nutrient.
To be honest I never thought of S as something they would need supplemented. My research was mostly along the "maybe I give them too much S when using epsom salt" lines. Now I did buy cal mag loaded zeolite that suposed to not have S. Will see if that makes them better or worse next grow. Its possible that now they are N defficient, cause i did not give them any nutrients during the last 3-4 weeks, left them to show deffs in hopes we can figure out what is really missing. But when I did feed enaugh to fix or almost fix the deffs... well.. They were blue, and I am pretty sure it was from too much N. As the very concentrated Ca product also has about 10-15 % avalable N. I did not manage to fix the cal mag deffs by using epsom salt alone. As I added 2 tablespoons into the soil mix and then 2 more table spoons at transplant time, I guess we should not see Ca deffs, since they did not grow much since then.
For reasons above, and also because it's not easy to figure out, I would incline to belive we are having some kind of ph or nutrient interaction problem. My guess is this is above my experience, since its not solved yet, so I would love to have any theories from people that are more experienced than me. What should I look for?
OFC, i know I ask alot of you guys and I hope to find the time to post full plant pics soon.
But my real life is keeping me busy a lot during the lights on time, so it may take a couple of days more till I get to that.
What to do with the plants I still have? The light is over 40 cm away and dimmed to 50%.
Should I throw a bit of epsom salts at them? Or some cal mag loaded zeolite? See if at least the apparent Ca deffs get fixed? Any other plans or suggestions?
Forgot to add I've seen problems like this over summer in 27-30 C grow about as much as in my fall/winter grows that are 20-25 C.
 
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