Light burn or?

[DWCgrower406]

Growing 4 plants in dwc. 3 plants same strain, different phenos, plus one plant completely different strain. Plants are pretty large and 2 weeks into flower. 3 weeks ago or so i noticed a couple leaves here and there getting some burned edges, nothing bad. Took the nutes down a tad and stayed on schedule, put them into flower. It has since gotten progressively worse. New growth looks fine and first signs of flower showing, but more leaves drying up and falling off every day. My conditions are perfectly controlled. Sealed room with originally 1500ppm co2, 83f, and 65rh. I have since dialed it back to 900ppm co2 and 78f to see how they respond, no change. Running cultured solutions nutes (with ro) which is designed for dwc and i know gives excellent results when running recommended schedule. I am at 425ppm right now and they are eating/drinking just fine. Ppm drops slightly over time as it should. I am doing full change outs every 5 days right now just to ensure it is staying balanced. Keep in mind this looks identical on 3 different phenos and another strain so i very much doubt its some odd deficiency. My ph and ppm is monitored by guardian. I let ph drift from 5.7 to 6.2. I very much doubt this is a nute problem.
To me this looks like light burn but i dont see how it could be. Its a 1000hps in sealed vented hood 3 feet from canopy and oscillating fans. I dont even feel any warmth on the back of my hand at canopy. I took some lux readings and get about 55k at the very highest. The burned leaves are definitely more prevalent right under the light but could this really be light burn at 3 feet away?

 

[Soul Dwella]

I know jack about DWC, but a couple things that popped in my head were res temps? and how is the oxygen/bubbles?

 

[curious2garden]

Growing 4 plants in dwc. 3 plants same strain, different phenos, plus one plant completely different strain. Plants are pretty large and 2 weeks into flower. 3 weeks ago or so i noticed a couple leaves here and there getting some burned edges, nothing bad. Took the nutes down a tad and stayed on schedule, put them into flower. It has since gotten progressively worse. New growth looks fine and first signs of flower showing, but more leaves drying up and falling off every day. My conditions are perfectly controlled. Sealed room with originally 1500ppm co2, 83f, and 65rh. I have since dialed it back to 900ppm co2 and 78f to see how they respond, no change. Running cultured solutions nutes (with ro) which is designed for dwc and i know gives excellent results when running recommended schedule. I am at 425ppm right now and they are eating/drinking just fine. Ppm drops slightly over time as it should. I am doing full change outs every 5 days right now just to ensure it is staying balanced. Keep in mind this looks identical on 3 different phenos and another strain so i very much doubt its some odd deficiency. My ph and ppm is monitored by guardian. I let ph drift from 5.7 to 6.2. I very much doubt this is a nute problem.
To me this looks like light burn but i dont see how it could be. Its a 1000hps in sealed vented hood 3 feet from canopy and oscillating fans. I dont even feel any warmth on the back of my hand at canopy. I took some lux readings and get about 55k at the very highest. The burned leaves are definitely more prevalent right under the light but could this really be light burn at 3 feet away?

Light burn would show regularly over the entire canopy. This is nutrient burn, but your reported PPM shouldn't give you that. What a conundrum, best of luck.

 

[DWCgrower406]

I know jack about DWC, but a couple things that popped in my head were res temps? and how is the oxygen/bubbles?

Both are excellent. Chiller set to 68, large commercial air pump.

 

[DWCgrower406]

I Will also add that my roots are very healthy with consistent growth. Im really stumped here. One thing ive learned over time is how difficult if not impossible it is to diagnose and treat a deficiency/excess of a specific element. Even if you know what the element is, the cause for that lockout could be a number of undeterminable things. 99% of the time, the best coarse of action to fix plant problems is making sure your environmental conditions are perfect and they are getting a proven balanced set of nutrients at the lower end of ppm. Very easy with dwc since you can dump res at any time and start fresh. I have done all these things and these plants should be thriving. As unlikely as it sounds, all i can do is treat for light burn by reducing light further and bring conditions down to minimal stress levels. Ill drop co2 to 400 or so as they would get outside and drop temp to 75.

 

[SamirK]

Hi, did you solve your problem? I’m having the exact same problem

 

[getogrow]

I Will also add that my roots are very healthy with consistent growth. Im really stumped here. One thing ive learned over time is how difficult if not impossible it is to diagnose and treat a deficiency/excess of a specific element. Even if you know what the element is, the cause for that lockout could be a number of undeterminable things. 99% of the time, the best coarse of action to fix plant problems is making sure your environmental conditions are perfect and they are getting a proven balanced set of nutrients at the lower end of ppm. Very easy with dwc since you can dump res at any time and start fresh. I have done all these things and these plants should be thriving. As unlikely as it sounds, all i can do is treat for light burn by reducing light further and bring conditions down to minimal stress levels. Ill drop co2 to 400 or so as they would get outside and drop temp to 75.

im not seeing "light burn" either. i agree with curious2.
maybe up the feed instead of leaving it low.

 

[DWCgrower406]

im not seeing "light burn" either. i agree with curious2.
maybe up the feed instead of leaving it low.

Yeah, i agree theres just no way it could be from lights when they are 3 feet away in glass vented hood. I tried raising ppm, lowering ppm, still continued to progress. After thinking back, its seems to me this started roughly around the time i switched to a sealed room with co2. Since then i have been able to keep conditions perfect (temp, humidity, co2) so the only other possibility i can think of is an off gassing of something in the room that never built up before as a vented setup. A couple possibilities, i did paint the room with mold resistent paint a couple weeks before starting the grow. Maybe the paint is letting something off and building up in the sealed room. Would make sense that mold resistent paint would have something in it that organic material doesnt like. Also this room is a repurposed bathroom. My water station is an ro setup with large tank sitting in a walk in shower. I would assume the drain has some sort of p-trap to prevent septic gases, but maybe its not functioning properly and i could be building up methane or something. About a week ago i shut down the co2 and went back to vented. It seems to have stabilized but i wouldnt conclude anything for sure from that. This grow definitely took a huge hit. I basically skipped the whole stretch period of flower. They were mostly at a stand still for first 2 weeks of flower so did not get that stage of massive growth that they should have. Also lost a huge amount of foliage. This is just for personal so not a huge deal. Hopefully get a half pound or so and try again. Maybe do a hybrid setup. Sealed with venting a few times a day. No idea if that was the issue, but i just dont know what else to look at. Nute levels were fine and 2 different strains showed exact same symptoms at same time. There is one other possible variable. I started this grow on gh flora with hydrogaurd for first month of veg, then switched to cultured solutions with uc roots which killed off all bene's and went to sterile grow. They handled the switch fine and looked great for first 2 weeks on cs nutes, but maybe the bene's resisted being completely killed off and caused problems later. Next grow will be sterile with cs nutes from start. All i can do is try again with the mentioned changes and hope it goes well. Maybe next grow ill throw 1 small plant in dirt along with rdwc so if i see a widespread problem like this again, ill know its environmental if dirt plant is also affected.

 

[The Dankstar]

A lot of people that use c02 vent a few times a day. Whats your c02 level and light level at? Doesnt look like defency of nutes to me looks straight dead. I would stop running c02 for a while and see how new growth looks.

 

[DWCgrower406]

A lot of people that use c02 vent a few times a day. Whats your c02 level and light level at?

I started co2 at 1500ppm with 83f ambient, after problem started i tried dropping to 900ppm and 78f to try and reduce stress for recovery, no change. Light is a 1000hps in a 5x5. Glass vented hood, 3ft from canopy. I dont have par meter but i was getting about 50k lux at center, 35k lux further out. Oscillating fans, no warmth on hand at all. Definitely nothing that should cause burn. Now im using no co2, vented. And 75f ambient. Damage has slowed but i cant say for sure why

 

[The Dankstar]

Good job. Stop running c02 and give it a week or so to recoup. With 1000 hps and 1500 ppm plant is pretty much maxing the max. Not sure if you need to adjust nutes for that much i've never ran a setup like that. I'd get the light away still 1000w is a lot of juice. Without par numbers i can't help you on that part I know the sweet spot for my plants in FLOWER is like 800-850 par. 600 area in veg. Norm the 1k hps at 3ft prob fine but since they are hurting I always back off a bit idk if you have a 600 bulb you can run for a bit until they heal. If it was me thats what I would do, some other people might be able to help you more. Good luck.

 

[getogrow]

Its all in your medium. I have no clue what the problem is but its not light or environment. Its in the feeding.

 

[furnz]

Potassium def by the looks. Dont go above 5.9 ph and up your ppm to 550 or so.
If its not that, its light stress.

 

[KambleFrost]

That looks like K def IMO

 

[Jimeeb]

Lol and yet another opinion. I say magnesium def. Sorry to throw another at ya.
Good luck to you.
Keep on growing.

 

[Jimeeb]

Growing 4 plants in dwc. 3 plants same strain, different phenos, plus one plant completely different strain. Plants are pretty large and 2 weeks into flower. 3 weeks ago or so i noticed a couple leaves here and there getting some burned edges, nothing bad. Took the nutes down a tad and stayed on schedule, put them into flower. It has since gotten progressively worse. New growth looks fine and first signs of flower showing, but more leaves drying up and falling off every day. My conditions are perfectly controlled. Sealed room with originally 1500ppm co2, 83f, and 65rh. I have since dialed it back to 900ppm co2 and 78f to see how they respond, no change. Running cultured solutions nutes (with ro) which is designed for dwc and i know gives excellent results when running recommended schedule. I am at 425ppm right now and they are eating/drinking just fine. Ppm drops slightly over time as it should. I am doing full change outs every 5 days right now just to ensure it is staying balanced. Keep in mind this looks identical on 3 different phenos and another strain so i very much doubt its some odd deficiency. My ph and ppm is monitored by guardian. I let ph drift from 5.7 to 6.2. I very much doubt this is a nute problem.
To me this looks like light burn but i dont see how it could be. Its a 1000hps in sealed vented hood 3 feet from canopy and oscillating fans. I dont even feel any warmth on the back of my hand at canopy. I took some lux readings and get about 55k at the very highest. The burned leaves are definitely more prevalent right under the light but could this really be light burn at 3 feet away?

Check this out.

Guide to Nutrient Deficiency or Toxicity

So 99% of the times I come in here to see what people are up to and check what forum threads I can throw some advice in, its plant issues. "theres yellowing" or "leaf is dry and brittle" or "OMG SPOTS!" so instead of using the 'cut and paste' tools, over and over all day, like I feel I have...

www.rollitup.org

 

[Jimeeb]

Check this out.

Guide to Nutrient Deficiency or Toxicity

So 99% of the times I come in here to see what people are up to and check what forum threads I can throw some advice in, its plant issues. "theres yellowing" or "leaf is dry and brittle" or "OMG SPOTS!" so instead of using the 'cut and paste' tools, over and over all day, like I feel I have...

www.rollitup.org

This is not my thread. It is thanks to nick17gar. I merely copied and pasted.

 

[lokie]

<apound!

 

[DWCgrower406]

At this point im pretty convinced this was not nutrient related. This happened to 4 plants simultaneously, 3 different phenos of one strain and another entirely different strain. This was using a proven nutrient schedule (cultured solutions) that works for most as is just by following exactly. Obviously some plants will want more or less of something and its very possible to run into issues when following a proven schedule, but 4 different plants simultaneously having exactly the same deficiency while being fed a well rounded schedule just doesnt make logical sense at all. The schedule works for most so how could it suddenly cause the same issue for 4 different plants at exactly the same time? Ph could do that, but im using bluelab gaurdian which was checked multple times with fresh packets of calibrator throughout this whole ordeal.
I am now pretty sure this was an off gassing issue of something in my room. This started not long after going sealed with co2 and finally stabilized not long after going back to vented. Unfortunately 2 of the plants just lost too many leaves so i chopped them. One of the 2 remaining was still pretty bad, but an extremely frosty pheno and should still yeild a couple oz. The other remaining plant recovered pretty well before losing too many leaves and should yield maybe 5oz. Its 7 weeks in now with a couple left, looking very nice.
As for the off gassing, my main suspect is the paint. I decided to give the room a fresh coat of white paint for reflectivity and i thought it would be a good idea to use mold resistent paint just to reduce the chance of spores taking hold somewhere. I have no idea what they use to make it mold resistant but im guessing its something not friendly to organic things in general (like plants). I started this grow only about a week after painting. This first month went fine as a vented room, no chance for gasses from paint or whatever it was to build up. Decided to go sealed with co2, mostly to make it easier to control temp and humidity since i dont have to rely on outside conditions. It worked perfectly and i was able to set temp and humidity exactly where i want to nail vpd. At that point the plants should have only done better but instead started going downhill steadily for weeks until finally trying going back to vented since i was out of ideas. That seemed to work.
For now i will stay with a vented setup since its working but eventually i want to go back to sealed, especially during winter so i dont have to fight against the cold dry air im sucking in. Might do a setup that dumps the room every few hours but that will cost a lot more in co2. Really i just need to solve the off gassing issue, but not sure how. The paint is just my best guess, it could be anything.

 

[getogrow]

At this point im pretty convinced this was not nutrient related. This happened to 4 plants simultaneously, 3 different phenos of one strain and another entirely different strain. This was using a proven nutrient schedule (cultured solutions) that works for most as is just by following exactly. Obviously some plants will want more or less of something and its very possible to run into issues when following a proven schedule, but 4 different plants simultaneously having exactly the same deficiency while being fed a well rounded schedule just doesnt make logical sense at all. The schedule works for most so how could it suddenly cause the same issue for 4 different plants at exactly the same time? Ph could do that, but im using bluelab gaurdian which was checked multple times with fresh packets of calibrator throughout this whole ordeal.
I am now pretty sure this was an off gassing issue of something in my room. This started not long after going sealed with co2 and finally stabilized not long after going back to vented. Unfortunately 2 of the plants just lost too many leaves so i chopped them. One of the 2 remaining was still pretty bad, but an extremely frosty pheno and should still yeild a couple oz. The other remaining plant recovered pretty well before losing too many leaves and should yield maybe 5oz. Its 7 weeks in now with a couple left, looking very nice.
As for the off gassing, my main suspect is the paint. I decided to give the room a fresh coat of white paint for reflectivity and i thought it would be a good idea to use mold resistent paint just to reduce the chance of spores taking hold somewhere. I have no idea what they use to make it mold resistant but im guessing its something not friendly to organic things in general (like plants). I started this grow only about a week after painting. This first month went fine as a vented room, no chance for gasses from paint or whatever it was to build up. Decided to go sealed with co2, mostly to make it easier to control temp and humidity since i dont have to rely on outside conditions. It worked perfectly and i was able to set temp and humidity exactly where i want to nail vpd. At that point the plants should have only done better but instead started going downhill steadily for weeks until finally trying going back to vented since i was out of ideas. That seemed to work.
For now i will stay with a vented setup since its working but eventually i want to go back to sealed, especially during winter so i dont have to fight against the cold dry air im sucking in. Might do a setup that dumps the room every few hours but that will cost a lot more in co2. Really i just need to solve the off gassing issue, but not sure how. The paint is just my best guess, it could be anything.

i HIGHLY doubt its the off gas of paint. Its a very good thing to think about though. Means your really thinking here.

When you added co2 an sealed everything up , did you up your food by a LOT ? More co2 means more food is neeeded to accomplish the same results.

Honestly there is no such thing as a food schedule that works for everyone. Its very rare but i have had a couple phenos over the years that cant handle much food at all. (FFOF can get throughj the whole cycle without repotting. like i said that is very rare)
How is your temps and rh ? i dont care about vpd....i just want the real numbers.