problems with quantum boards(yellowing)

[Frosty Nuggets]

I haven't had any problems with my LED's, the plant is growing fast.

 

[GMT]

You do have yours a safe distance away though frosty.

 

[Only The Best]

Hi,

Light height is fine then

How much Mg did you give them per litre? Your plants need a lot, plus iron and trace elements. Sometimes Mg and iron deficiency look the same.

Did your plants start off losing colour like the picture of the plant below?



This is a picture of my Northern Lights under the QB. This was the start of a Mg and (maybe) an iron deficiency. I corrected it by adding CalMag for every watering until the problem disappeared, and it took a while. I don’t like using mineral CalMag and have since found an organic substitute. At the time I knew I had to fix the problem fast. The brand I used had Mg, Cal, Iron plus trace elements.

Your plants still need N during flower. When the plant transitions from vegetative growth to flowering, you should still be feeding Nitrogen feed so the plant has enough throughout flower, at least two weeks into the flowering period depending on variety. I found my plants under QBs needed more. I had to completely change my feeding regime under QBs!

I’m no longer using QBs because I wanted something more powerful and opted for single led cob units that I could have at different heights depending on plant height.

I’m still not sure what medium you’re using as I haven’t read the entire thread. I grow organically in soil and the above worked for me. If you’re hydro or coco then your problems might be PH/nutrient lockout.

i give my plants 1ml cal mag per litre of water before 12 days when i change the nutrients from the system...and yes,my plants was exactly like your plant at the first stage of my problem.
the fertilizers i use are GHE and the cal mag is also GHE.
Today i change the water with fresh nutrients, i add 1/1/1 micro,grow,bloom and 200ml cal mag,the plants are more sick then the photos i post.i notice almost zero stretch with the QBs.

Hmm I never used RWDC so I don't know much about what normally happens. if the plants take no nutrients at all but the water level decreases, then the EC should rise, right?

Indeed, if adjusting the light by itself hasn't fixed the problem to your eyes, it could be the case that your old nutrient strength is simply not doing the job.

Great post Kalbhairav.

As far as EC, I understand many people in RWDC use a low EC and find that the plants drink more the lower they go. EC doesn't tell evertyhing though. Even at 2 EC some A&B may not have enough Mg.

Whats happening now is a complex interaction between light intensity, leaf temperature, nutrient strength, etc.
Difficult to trouble shoot in a short time

You will find the way

My feed in flower has even more nitrogen than veg, and still, this happens.
View attachment 532997
According to the bro science that plant should be dark green, combust to 100% black ash and be unsmokable

.

I grow much higher EC but don't do DWC...1.2 sounds low to me, but since you have had success with it, I'm not one to comment
I wouldn't expect the old big leaves to green up quickly, but the new growth should look green & vigorous

Yes,today my ec was 1,4+., 1,2 in rdwc is ok even for the most hungry strains,imagine that i finished some malawis in the past with 0,6ec.today as i say and above i change the nutrients with different ratio..1/1/1 just to add more N,first time since i make rdwc grows i do this in 2 week of flower,time will tell

 

[THC123]

H GMT, giving more nutrients won't solve the problem at all this is purely light related. So like you said raise the light, lower light intensity.

I have had the exact same problem with my fluence, couldn't give them more than 100 pars at the recommended distance. Total yellowing. I then raised the light to 80-100 cm and then no yellowing but too low light intensity, so I raised it to 350 micromols and it was ok but still unhealhty weird plants. So I ditched that light.

For 2 months I broke my head trying to figure it out, I could not accept that it was the light. I had a par meter, I knew what they were getting and still those problems, for me it is still beyond logic. The only reason in my mind is that I have a faulty unit with some wrong colors in there, I dont know, but I know they are good lamps.

The same plants could take 500 micromol without problems with the Viparspectra V600 and thrived.

I also did side by sides with certain cuts that I am still vegging now. After 3 days under the fluence or bleaching or weird stunted growth, pale blueish color, droopy as if overwatered. (or they looked like yours if I kept light too close, now I am talking about when I raised the light, contrary to their instructions).

Those same cuts are now under a SF4000 with full power, and I even have seedlings under it. I don't know how far away the lamp is, but they get 300 micromoles at the moment and I have huge coverage. I hope your lamp is not an SF series lamp ?(cant scroll back to check while replying)

Point is I changed the spectrum by changing lamps and problems went away and now it is pretty much like any other grow (although I do feed more and use organic calmag + trace elements once a week preventively).

 

[Kalbhairav]

I agree and disagree THC123

Yes, the light is the key factor, and yes raising the light will stop the yellowing.

The plants though will not be getting the benefit of what the light has to offer if it’s 50 - 100cm away from the canopy.

The plants begin to pale/yellow because of a number of different factors. Paying attention to all these factors and refining the plants nutritional needs will absolutely solve the problem.

It has with me (although I grow in soil) and I’m now happy at 35cm from the canopy at 100% power (2 x 100w Migro 3.5k cobs at present although was using an Invisible Sun QB). I have no yellowing at all. Only pure green and vibrant plants.

If Mg, Iron and trace elements (like sulphur for instance) are given to the plant in higher amounts then the plant will be able to use the readily available N (if of course there’s enough in the feed) much more freely to tune itself to the light intensity.

I was lucky in the fact that I had other growers who had already figured this out.

If growers want to continue using their old feeding regimes and have their LEDs at half power and miles away from the canopy, then good luck to them. To each their own..

 

[THC123]

My point is that I only had this issue with one light, with 2 other lights I didn't, I can also keep those leds at a normal distace at full power, so what you are saying, depending on the LED's spectrum you have to make these adjustments?

I also grow in soil organic.

 

[Kalbhairav]

My point is that I only had this issue with one light, with 2 other lights I didn't, I can also keep those leds at a normal distace at full power, so what you are saying, depending on the LED's spectrum you have to make these adjustments?

I also grow in soil organic.

I’m by no means an expert and haven’t had the pleasure of growing under 4K as of yet. I was under the impression that 4k has too much blue for flowering.

My opinion is only based on my grows under a 3k Quantum Board and the 3.5k cobs I’m currently using. Even these two lights differ; the QB LEDs being uncovered while the cobs are covered with refractors. With the light hitting the glass first you get less intensity.

From my experience from the grows with the 3k QB I had to totally adjust the way I fed my plants. In past experience using HPS and
growing outdoor, I never had to amend with lime or epsom unless I saw an Mg deficiency late in flower. With the QB I immediately had discolouring in my plants in early veg (below is a link to my Northern Lights grow where all this happened).

https://www.icmag.com/ic/showthread.php?t=368785

As you might read in my thread, I was adamant that my problems weren’t because of plant nutrition, even when most people were saying it was. I eventually went with their suggestions and started to amend with Epsom salts. This helped but didn’t solve the problem. I then bought an calmag product that also had iron and trace elements in it. Within a couple of waterings my plants were coming flying back to full health. I upped the power and lowered the light and had a good harvest.

I have since swapped for a plant based organic calmag and haven’t had any problems since.

Of course, this might not be the answer for everyone. As I’ve stated, I’m not familiar with hydro and the OPs problem might have to be solved differently. But, from the look of his plants, it for sure can be fixed either by adjusting his PH, or adding much needed N and Mg (plus iron, possibly), or both.

 

[Shmavis]

Hi,

Light height is fine then

How much Mg did you give them per litre? Your plants need a lot, plus iron and trace elements. Sometimes Mg and iron deficiency look the same.

Did your plants start off losing colour like the picture of the plant below?

View Image

This is a picture of my Northern Lights under the QB. This was the start of a Mg and (maybe) an iron deficiency. I corrected it by adding CalMag for every watering until the problem disappeared, and it took a while. I don’t like using mineral CalMag and have since found an organic substitute. At the time I knew I had to fix the problem fast. The brand I used had Mg, Cal, Iron plus trace elements.

Your plants still need N during flower. When the plant transitions from vegetative growth to flowering, you should still be feeding Nitrogen feed so the plant has enough throughout flower, at least two weeks into the flowering period depending on variety. I found my plants under QBs needed more. I had to completely change my feeding regime under QBs!

I’m no longer using QBs because I wanted something more powerful and opted for single led cob units that I could have at different heights depending on plant height.

I’m still not sure what medium you’re using as I haven’t read the entire thread. I grow organically in soil and the above worked for me. If you’re hydro or coco then your problems might be PH/nutrient lockout.

Kalbhairav nailed it. The plants want to grow quickly under led, so they canabalise the nitrogen from the bottom shaded leaves. People reach for the cal mag to aid in that, but forget the iron. Either give them more nitrogen, add some iron to the cal mag, or raise the lights so they don't grow as quickly. Any of those will help a lot. I'm still feeling my way around led too, so there may be other solutions yet. Oh I suppose you could turn the light power down too and save some electric.

As some may know, wave: Kal), I too struggle with QB growing after many years under HID. I have been using the same soil mix for 15+ years and never added lime to it. Not only did I add lime to my mix this last time to up Cal & Mag but also I was adding epsom with every watering, seeing as how Mg hungry nearly all plants under QB seem to be. Every few waterings or so I would also add some gypsum. Recently had a good deal of yellowing on a plant even with the additional inputs. Chose gypsum and epsom in an attempt to be somewhat organic. Given the continued yellowing I said hell with it and added 4ml of Botanicare's CalMag +. Watered one day at lights on and 24hrs later saw a big difference. In the pic you can see where the coloring changed from the yellowing. 24hrs before there was no purpling - only yellow. Quite the shock to see the change the next day.

What's the + in the bottle? Iron. So think you two may be on to something with the call for extra iron.

I also feel there's a need for more N in my mix under QB and may add extra EWC next mix. But all in all there's so much tweaking required under QB that I do not think I will continue down this path and am strongly considering going back to HID in the fall to see how things compare... I imagine these issues are easier to overcome in mediums other than soil.

In short, I do not have answers but wishing OTB nothing but the best of luck with the QB ventures.

 

[THC123]

I’m by no means an expert and haven’t had the pleasure of growing under 4K as of yet. I was under the impression that 4k has too much blue for flowering.

My opinion is only based on my grows under a 3k Quantum Board and the 3.5k cobs I’m currently using. Even these two lights differ; the QB LEDs being uncovered while the cobs are covered with refractors. With the light hitting the glass first you get less intensity.

From my experience from the grows with the 3k QB I had to totally adjust the way I fed my plants. In past experience using HPS and
growing outdoor, I never had to amend with lime or epsom unless I saw an Mg deficiency late in flower. With the QB I immediately had discolouring in my plants in early veg (below is a link to my Northern Lights grow where all this happened).

https://www.icmag.com/ic/showthread.php?t=368785

As you might read in my thread, I was adamant that my problems weren’t because of plant nutrition, even when most people were saying it was. I eventually went with their suggestions and started to amend with Epsom salts. This helped but didn’t solve the problem. I then bought an calmag product that also had iron and trace elements in it. Within a couple of waterings my plants were coming flying back to full health. I upped the power and lowered the light and had a good harvest.

I have since swapped for a plant based organic calmag and haven’t had any problems since.

Of course, this might not be the answer for everyone. As I’ve stated, I’m not familiar with hydro and the OPs problem might have to be solved differently. But, from the look of his plants, it for sure can be fixed either by adjusting his PH, or adding much needed N and Mg (plus iron, possibly), or both.

I always use magnesiumlime for calmag i my mix (way before leds as well)x, then there is also calmag in the rockdust I use and 60 trace minerals slow release good quantities and then I have the worm castings that also contain trace minerals and they make the stuff in the rock dust available for the plant while containing trichoderma and mycorhizzae(I also added these seperately). I think it will go okay, but just in case, as it is my first time flowering with the sf4000 I also have epsom salts and an organic trace mineral mix. Under the viparspectra I usually had a bit of deficiency towards the end before I amended.

I looked at your thread but you just had minor bleaching(like I had with my vipar towards the end) and that was clearly Mg deficiency. I had plants almost dying it was pure lightbleach no deficiency, also looked different than your issue. The yellow leaves got crispy and died off.

 

[THC123]

As some may know, wave: Kal), I too struggle with QB growing after many years under HID. I have been using the same soil mix for 15+ years and never added lime to it. Not only did I add lime to my mix this last time to up Cal & Mag but also I was adding epsom with every watering, seeing as how Mg hungry nearly all plants under QB seem to be. Every few waterings or so I would also add some gypsum. Recently had a good deal of yellowing on a plant even with the additional inputs. Chose gypsum and epsom in an attempt to be somewhat organic. Given the continued yellowing I said hell with it and added 4ml of Botanicare's CalMag +. Watered one day at lights on and 24hrs later saw a big difference. In the pic you can see where the coloring changed from the yellowing. 24hrs before there was no purpling - only yellow. Quite the shock to see the change the next day.

View Image

What's the + in the bottle? Iron. So think you two may be on to something with the call for extra iron.

I also feel there's a need for more N in my mix under QB and may add extra EWC next mix. But all in all there's so much tweaking required under QB that I do not think I will continue down this path and am strongly considering going back to HID in the fall to see how things compare... I imagine these issues are easier to overcome in mediums other than soil.

In short, I do not have answers but wishing OTB nothing but the best of luck with the QB ventures.

Do you have a par meter?

It is perfectly doable in soil! For me there is no real tweaking apart from more nutrients in the mix and more trace minerals and calmag. For the rest just water

 

[Only The Best]

my friends thanks for the answers..unfortunately i dont really know what to do and today i turned off the one light and hang the other in the middle of the tent,i know is not for 2,4x1,2 but i want to see if
i have some impovent with just one light..i raised my ec also to 1,6.
....i think this thread must stay alive because i notice that many people of the community had problems with the QBs,.

my lights are SF4000 450w from spider farmer
and KINGBRITE 480w with cree uv ir..

 

[Kalbhairav]

Sorry to hear the problem is persistent OTB, I’m sorry I can’t be of any more help.

Hopefully somebody who has good knowledge of hydro and is using QBs successfully will chime in.

I hope you get you can get through and have successful grows with your set up in the future.

All the best

 

[THC123]

Damn yeah thats my light, strange, here this lightt causes no issues. DO you know which one of the two is causing issues? Have you tested this? ANd do you know how much ppfd they are getting? On ebay you can buy a quantum par meter for only 150 dollars. very handy tool for growing with LED. With the naked eye it is impossible to tell the difference between 300 and 500 ppfd.

 

[Shmavis]

Do you have a par meter?

It is perfectly doable in soil! For me there is no real tweaking apart from more nutrients in the mix and more trace minerals and calmag. For the rest just water

I do. It's not an expensive one though. Started with a lux meter and an online conversion calculator. Questioned the accuracy of such a method. So got the cheaper model of a PAR meter.

The light that you had all the issues with, what's the color temp? I have a 3500K COB panel that gives me fewer problems. My QB is 3000K.

I don't deny it's doable in soil but man after adding lime and then watering with extra Mg each time and still experiencing the yellowing is discouraging, to say the least.

H GMT, giving more nutrients won't solve the problem at all this is purely light related. So like you said raise the light, lower light intensity.

I have had the exact same problem with my fluence, couldn't give them more than 100 pars at the recommended distance. Total yellowing. I then raised the light to 80-100 cm and then no yellowing but too low light intensity, so I raised it to 350 micromols and it was ok but still unhealhty weird plants. So I ditched that light.

For 2 months I broke my head trying to figure it out, I could not accept that it was the light. I had a par meter, I knew what they were getting and still those problems, for me it is still beyond logic. The only reason in my mind is that I have a faulty unit with some wrong colors in there, I dont know, but I know they are good lamps.

The same plants could take 500 micromol without problems with the Viparspectra V600 and thrived.

I also did side by sides with certain cuts that I am still vegging now. After 3 days under the fluence or bleaching or weird stunted growth, pale blueish color, droopy as if overwatered. (or they looked like yours if I kept light too close, now I am talking about when I raised the light, contrary to their instructions).

Those same cuts are now under a SF4000 with full power, and I even have seedlings under it. I don't know how far away the lamp is, but they get 300 micromoles at the moment and I have huge coverage. I hope your lamp is not an SF series lamp ?(cant scroll back to check while replying)

Point is I changed the spectrum by changing lamps and problems went away and now it is pretty much like any other grow (although I do feed more and use organic calmag + trace elements once a week preventively).

I also have VIPARSPECTRA LED panels and do not encounter the same issues in the same soil mix.

 

[THC123]

I also have VIPARSPECTRA LED panels and do not encounter the same issues in the same soil mix.

Ok so same as me, so with same light intensity under vipar no issues if I understand correctly (no native speaker)

The light I have issues with the fluence spydrx is supposedly 4000 k according to customer service

The one from spider farmer is 3000 and 5000k.

Yeah like I said I use a lot of lime in my mix and also rock dust which is also full of calmag but slow release and the worm castings also have calmag. Sometimes, if I see leaves are green but don't shine no more I spray calmag and in flower water with it. Before flowering I topdress with a mix of soil 12-14-18, compost worm casting more lime and rock dust etc... so they always have a steady supply


But up to now almsot never. That being said, I am also no LED expert, only did 3 grows up to now with LED and this is first time with the newer white leds like sf4000 and fluence

 

[Shmavis]

Ok so same as me, so with same light intensity under vipar no issues if I understand correctly (no native speaker)

The light I have issues with the fluence spydrx is supposedly 4000 k according to customer service

The one from spider farmer is 3000 and 5000k.

Yeah like I said I use a lot of lime in my mix and also rock dust which is also full of calmag but slow release and the worm castings also have calmag. Sometimes, if I see leaves are green but don't shine no more I spray calmag and in flower water with it. Before flowering I topdress with a mix of soil 12-14-18, compost worm casting more lime and rock dust etc... so they always have a steady supply


But up to now almsot never. That being said, I am also no LED expert, only did 3 grows up to now with LED and this is first time with the newer white leds like sf4000 and fluence

Thanks for the info. I have a couple 4000K panels I bought to start seedlings under and they got fried at recommended distance.

Yes, that's what I meant. PAR readings not exactly the same but very close. No issues under blurple but that's not the case under the white light. I even grew some clones outdoors in my soil mix to see if the problems were in fact being driven by the light. The clones did fine outdoors with no additional inputs. Maybe I just need to really beef up my mix under LED.

Anyway, don't mean to derail or hijack the thread, but just wanted to say I too find the white LED to be challenging.

Good luck, OTB.

 

[bigpeter]

The first plant I ever put under my sf2000 got fried, it was under a low powered blurple and I thought it would do well under the new lamp. I was wrong and concerned as I wasn't sure why it got fried. My present grow was started from a seed 30 inches from the lamp and its doing very well. Coco drain to waste hand watered twice a day. This pic the lamp was about 13 inches above not dimmed.

 

[Only The Best]

Sorry to hear the problem is persistent OTB, I’m sorry I can’t be of any more help.

Hopefully somebody who has good knowledge of hydro and is using QBs successfully will chime in.

I hope you get you can get through and have successful grows with your set up in the future.

All the best

the problem is that i dont find the problem,i feel like a jerk after 16 years of successfull grows that i deside to change the hps with leds.

Damn yeah thats my light, strange, here this lightt causes no issues. DO you know which one of the two is causing issues? Have you tested this? ANd do you know how much ppfd they are getting? On ebay you can buy a quantum par meter for only 150 dollars. very handy tool for growing with LED. With the naked eye it is impossible to tell the difference between 300 and 500 ppfd.

both of them causing issues and i dont know if a par meter will help me now.the sure think is that i nevered had the lights to close.

The first plant I ever put under my sf2000 got fried, it was under a low powered blurple and I thought it would do well under the new lamp. I was wrong and concerned as I wasn't sure why it got fried. My present grow was started from a seed 30 inches from the lamp and its doing very well. Coco drain to waste hand watered twice a day. This pic the lamp was about 13 inches above not dimmed.


View Image

nice buds btw..did you find the reason why you fried the first plant?

 

[bigpeter]

did you find the reason why you fried the first plant?

I think my problem was caused by putting my plant under the sf2000 right up close during early flowering when it had been used to to low powered blurple, the leaves went yellow the petioles went purple / red, the shock was too much for the plant. I did get some smokable buds but it was a poor harvest.

 

[DiverDave]

Lite Changes

Lite Changes

The first plant I ever put under my sf2000 got fried, it was under a low powered blurple and I thought it would do well under the new lamp. I was wrong and concerned as I wasn't sure why it got fried. My present grow was started from a seed 30 inches from the lamp and its doing very well. Coco drain to waste hand watered twice a day. This pic the lamp was about 13 inches above not dimmed.


View Image

One thing I learned the hard way and I will stick to it.
If you start out with high intensity lights , all good .. If you use low intensity and switch to high intensity you either raise them or dimm them.
Its easier to start with high intensity White and later augment them with plurple in flower.
Eventually I will do a grow to document that , right now I have dialed in my bio-buckets and experimenting with many lights mostly COBs and Leds.
I feel the QB is a hot unit and needs to be introduced to the plant from afar if in middle to a grow .. Shock is real. She feels it.

DD

p.s. I'm pulling up a chair , someone is bound to chime it great thread and nice bud shots.