Light Burn? Looks like she was in a deep fryer

Unfortunately damaged leaves will not recover and plant is far enough along it’s sending all it’s energy to flower. Best to let it ride and do a good defol ahead of harvest.

Remember too that the plant is dying. That’s just a part of flowering off to harvest. So some of the damage can be attributed to senescence of the plant.

Did you keep track of when flowering started? This is a really important datum that will inform your harvest timing. I don’t see any reason you couldn’t let the plant finish and no reason you can’t admire your trichomes: it’s your plant! lol.

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The plant is suffering from a major deficiency that at this point is so far along you cant stop it. The leaves may get worse but it can for sure still be finished out and have great smoke.
I had this happen on my first grow. Turned out a cal mag and phosphorus deficiency. Just be sure to use cal mag through the end. The plant will still finish out
Your lights can be both switches on. And 100% also as they are miles away from plant ,
Probably best to research plant deficiencies so you know what to look for. When you first see signs of deficiency it has to be addressed right away because it takes some time for them to show on the leaves and continue to get worse before better even after addressing the problem. So the faster you catch a deficiency the better.

Also with super soils I think people who use them will top dress with dry amendment throughout grow with different things dependent on what the plant needs. Best to research that as well.

I will do just that, thank you!

Remember too that the plant is dying. That’s just a part of flowering off to harvest. So some of the damage can be attributed to senescence of the plant.

Yeah, I do forget that. Almost every ‘before harvest’ picture I see, the leaves are all almost dead. I see what you’re saying.

I did actually. I first noticed flowering on 5/19, so it’s been 6 weeks and 2 days today. I’m guessing slightly before or right at 60 days of flowering she might be done? Totally a loose timeline though. That’s just what the seed company says ‘max flower time’ is.

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The way the leaves are curling up though…I thought that was a key indication they were getting scorched?

It may look like a good distance in the photo, but the light is only 20" or so from the top of the canopy. I would think that would be close enough to do some damage at 100% power?

Good to know. Thank you for replying and your feedback!

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Light most likely recommends 18" height. Check with manufacturers recommended height.
On your next grow just be sure to have proper amendments for your super soil and you should be fine. Also be sure to water enough. Best of luck and happy growing !!

I’m pretty good with that. At full flowering, it calls for 20" + away from plant. I had it at 21." One thing to note though is that the tent is pretty tiny. So I think such a big light in such a small space caused the heat problems.

Will look at more amendments for the super soil.

Thanks for your reply!!!

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OooWee, looks more of a nutrient deficiency than a burn. Looks like your lights are more than enough, possibly to far, from your plants in the pictures. More than 14” is fat enough of you have good air circulation and temps are around 78deg.
My thoughts are you are in late stage flower and could be experiencing nutrient deficiencies.
Could be lockout or too much fertilizer.
Since the effected leaves are not confined to the top canopy I’d rule out light burn.
You should check your ph and ECC level.

I’m using General Hydroponics Flora series and am in late bloom too. I’m only using the GH Dry Bloom. When I’m doubt I just add water to my DWC hydroponic tanks after initial feeding for that week.

DWC hydroponics is so much more forgiving. If you have ph or ECC issues you can adjust immediately and within hours your plants should feel better.

With soil based medium you will have to add water your plants and collect run off to gather metrics on your plants ph and ECC levels. Then adjust accordingly. Then the waiting begins to see how they respond. If your plants are already wet and over watering is the issue then your doing harm just by adding water to collect the run off for analytics.

Looks like you’ve got a very nice setup and have invested for the long haul.
I’d recommend to take a look at DWC hydroponics. You’ll be amazed by the vigor your plants will display.
Small investment with a large payback.

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So, one thing I didn’t mention is that I was getting temps 88-91 during the day with the light on. With a tower fan blowing, and a top fan blowing. Not to mention the heat caused in my basement when my wife decides to do 40 loads of laundry at a time. (dryer heat) Currently, the light is 100% flower and 50% veg. Temps are now stable at 81-82 during the day with the light on. If you notice in the pics, only the leaves that are on top are curling up. The leaves under the canopy are still green.

I checked lockout, PH of runoff was 6.8/6.9. Should be good, right? I did not check the PPM’s however.

This has recently really caught my interest. I’ve had several other grows suggest this route as well. I believe it sounds more intimidating than it actually is. Much like growing weed in general seemed to be for me.

Really appreciate the sound advice and feedback on my plant! I will 100% look into DWC. Love how those roots look when growing this method :slight_smile:

Again, thank you very much for your reply/feedback!

I think the heat during the day is the culprit. Too much heat will cause your plant to close the Stoma which are pores that take in CO2. When this happens no CO2 can be taken for the photosynthesis. This shutting down the photosynthesis process.

May I suggest your change your light schedule to run lights on around 9pm and lights off at 9am. If this will bring your grow period temps down to 85 degrees or better your to around 77.5 degrees would be perfect.

That’s why I took the handle I have.

Check out this video….

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Check your plants again for any leaf damage. Looks like it could be heat related. Light burn would be top of plant including flower burn. Looks your leaf damage is from heat. Looks like some damage down past the top canopy.

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I wanted to include a photo of some Cherry Pie that I let get close, within 2 inches, to the lights. I did this on purpose to get the leaves to stress a bit and express the red pigment in its leaves. But, you have to keep ambient temperature in the 75-85 degree range. Got some Runts that express a deep purple too.
The Cannabis plant can use to 850 PPFD without supplementing CO2. You can check your light specifications for proper spacing.


I didn’t include that the Cannabis is a C3 plant. C3

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I agree with you. I don’t think it was so much the light, but the heat the light was blowing out that my 4" exhaust couldn’t get rid of. Since the heat seems to be stabilized now by turning the ‘veg’ light to 50%, do you think I can continue the grow like that? I have been looking at switching to 12/12 due to the hotter parts of the day but I’m a little concerned with basement light seeping into the tent during the dark period. I have a few pin holes here and there on the tent but I also have one of my 4" vents open at the bottom. (to suck in air outside the tent while the exhaust blows it out) I want to get into photo periods and I know how critical it is to have complete dark. Another grower on here told me that you just don’t want a large amount of light getting to them and pinholes won’t have any effect. Do you agree?

Very interesting…thank you! And thank you for your replies to my thread!!

I’ll have another look at her tonight and see if I can narrow the damage to the top of the plant or all around. I believe you are correct once again though, I think it’s heat related. Which makes me feel better about the light choice I picked.

Just curious, why did you want the leaves to show red pigment? Esthetically pleasing or does it have an effect on the bud?

PS - I noticed your leaves aren’t curling at all. Just a color change. Interesting.

Check current research on light spectrum. Although the Red shifted light is good for flower it will also cause some stretch. Blue light cause the plant to not stretch. Red does penetrate the canopy more than Blue but so does Green and current studies show it does provide photons for the photosynthesis process.

If you can cutout some cardboard to cover your windows or somehow tape over the pinholes, getting your temps below 85 degrees is pertinent to growing. Otherwise you can also checkout a plant that can thrive in hotter climates. I think Gelato and Durban Poison should work better with temps between 85-90 degrees.

Trying to push production by increasing PPFD while maintaining temperature and CO2 in productive levels. I monitor temp, relative humidity and CO2 levels and the only one out of spec is the CO2. I’ve been adding CO2 enhancers to try and keep them up.
I think cannabis can use up to 1500 PPFD but you must also maintain CO2 at 400 ppm and temperature around 77.5 degrees.

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