Spectra 290 2011 LED leaf problem in Soil and DWC cabinet

I have been reading RIU for about two years, but never posted for privacy reasons. Now I got a new light and my babies are dying so I had to take the risk and ask for help.

I have had like 10 grows, some of them perpetual, in different mediums. I have tried soil, a diy kind of NFT and now some dwc buckets for first time.

For all my grows I have been using GH with lucas formula + canna boost, pk13/14, rhizotonic, canazym with acceptable results for the 150w hps I had. The current growspace is about 40x75x160cm with 4" S&P fan for exhaust and a 14cm pc fan for intake.

My current grow is One Dutch passion-aurora in 6.5liter pot
Two clones of dutch passion-oasis in a 5lt dwc bucket and one dutch passion-ultimate in 5lt dwc bucket.

I vegged the seeds for about 3-4 weeks under 65w 6500k cfl. Then I put them all under the Spectra 290 2011 under 12/12 at about 14" from the canopy. There were also 3 clones on a nft slab with 15 days remaining till harvest.
Temps: max 26celcius Humid: around 50-55 ppm~1100 ph~5.9

For the first week to 10 days everything looked great and all of the plants were growing at an impressive rate.... Until some of the leaves on all plants started to give some spots and become yellow.
My initial thought was that I had the light was very close to the plants so I put it at 16-17". Left them a couple of days like that and they became worse.

I then came across a thread about PVC materials that release gases. I took the pvc ducting I had completely off, replaced the nuts in the buckets and watered the plant in the pot with 160ppm water as I was getting crazy. (Even though I previously used PVC ducting inline with a cooltube in my previous grows with no similar signs or problems). This was about 5 days ago.

Three days ago I took the panel at about 28" away from the plants.

At this point, and since they are at about the same state I wanted to ask for help from some more experienced growers.
I am not a total newbie, I just didnt have any big issues in my previous grows so I dont have much experience in troubleshooting.
I like to experiment with different setups to find what suits me best for my space and stealth needs.

I would really appreciate any input.
Thanks in advance for taking the time to read this long chunk of text

Some of the new leaves in the middle that have not yet become yellow seem to be in good condition and not deteriorate.
Would it be a good idea if I reduce the light to 10/14 for a couple of days?

so what have you changed since your last successful grow ?

Only the light. I previously had an 150w hps. and I got a spectra 290 LED.
Im going crazy because the light was my only main alteration, so this means that everything points to the light. But so many people have had successful grows with it. Irishboy was my main motivator for going into led lights. He has plenty successful journals with the spectra in RIU.

different feeding ratio then, better light = hungrier plants ?

I was initially feeding with 1300ppm, but since it started going bad, I decided to reduce it to 1000-1100. Is this even considered underfeeding?

I have the EXACT same problem with my current flowering plants. Every single one of them looks exactly like that. I also have a Spectra 290 2011 version. I raised my light up to 24" or so above canopy and it hasn't gotten worse, but it's still bad.

Edit: just re-read your post, 14" is about where mine was as well. Get that light higher, asap. This is NOT a little kiddie ebay LED, this thing is bright as balls

i doubt the light is doing it,,,could it be a cal/mag problem....But i know now to stay away from the Spectras...GL

try going back to hps for the rrest of this grow use led next time, could have shocked them. temp change at all?

temps are at 26-27 celcius range

this thread deserves a bump, im gonna try led soon, so im dead curious how it all goes for you buddy, and good luck too.

DinafemHashPlant said:

i doubt the light is doing it,,,could it be a cal/mag problem....But i know now to stay away from the Spectras...GL

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I dont get how it can be a cal/mag or any deficiency problem since I did like 10 successful grows with the exact same nutrients. Im not an expect, I just can't understand how can this be possible since I didnt change anything really.

stealther said:

I dont get how it can be a cal/mag or any deficiency problem since I did like 10 successful grows with the exact same nutrients. Im not an expect, I just can't understand how can this be possible since I didnt change anything really.

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mate, the guy you quoted sounds slightly ignorant, fk all wrong with your light and im certain you will work it out

I would like to know as well. Only thing I could think is since your running a cab, maybe temp difference in the soil. Looks like there is no heat at all in your cab. Would like to hear from others.

Just curious what is the nute mix youve been feeding them since you flipped to 12/12?

I Used the GH lucas formula plus Canna Boost and little Canazym varied from 1100-1300ppm

stealther said:

I dont get how it can be a cal/mag or any deficiency problem since I did like 10 successful grows with the exact same nutrients. Im not an expect, I just can't understand how can this be possible since I didnt change anything really.

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It is possible you shocked them. How long did you allow them to be under the light before removing it?

LED grows can result in a cal/mag deficiency due to the nature of the lights. That's why most LED growers use CalMag (or a similar product) to offset this issue.

already ordered some Grotek Cal-Max as the local shop didnt have any. lets see if I can revive them....

I use cal mag with my led grow. Spectras are good lights. I have one of their 100w ufos in my garden. I use mostly Pro Grows from Hydroponics Hut. Feel free to check the journal in my sig to see what I've done with mine. If you have them too close (less than 7 inches from the tips) the light intesity of the diodes will bleach the plants, but that doesn't look like bleaching in the pictures.

This is a very well documented provlem with the 2011 v1 lamps. Mike is takign returns on them for the v2 lamps. call or email him