Light burn woes: Autoflower Edition

Last April, I got a BESTVA Dimmable Pro4000W LED Grow Light in a 2×4 tent. 3 grows later, I’m still experiencing light damage. I’ve dimmed them and they’ve recovered beautifully. But I got a ppfd meter on my phone and the reading is pretty low for even the highest settings. I don’t my buds to suffer because I lower my lights too low. Any thoughts?

From previous grows including now:

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The unaffected plant:

The plant in question:

They are 27 days old.


Highest ppfd readings above the plants

The affected plant is Sweet Seeds Big DevilXL and the second one is Atlas Gummi Bears.


Have u checked your runoff numbers?


Man, that doesn’t look like light burn to me.


My android app photon (whatever) maxes at 33KLUX.
My new Light meter, UT383-BT ($30.00, Blue tooth) measures differently.
High Noon daylight, yesterday in winter, 1000LUX with x100 (100KLUX).
My lights on maximum will meter measure 33KLux with phone app.
Meter shows 70KLux max, before “too close” dimming occurs (reedings drop when up close to light).
700 real watts and I run the lights at 50Klux and 25 inches.

Meter includes useful software.
Vipar Spectra V1200 operates max 550 watts or halved for VEG/Flower switches.
The HLG 350R at 50% (200watts) will output the same LUX (smaller footprint, operates cooler).
Who knows what spectrum the VS does, but they grow flowers for my killing.


It isnt. That is good lights making plants hella hungry.

@Redfoxx1989 we need more specifics. Either your pH is out of wack, locking out available nutrients.

Or the available stuff she needs is not available anymore and you have to supplement it.

Pic number one looks hungry. Nitrogen most likely. Maybe K, i cant see it the best.

Picture 2 is a magnesium deficiency in full swing. The yellow boxes inside of green veins is a dead giveaway. I bet it turned brown then dried up a few days after the photo.

Picture 3 is the start of said magnesium deficiency. See yellow boxes. 4 is start of the same.

Now the runoff numbers or you grow answers will tell us how to approach the problem. If pH is out of range (6.3-6.8 in soil, 5.8-6.2 in coco/hydro) then you adjust into range. If ppm/tds/ec is low, you add nutrients. Namely calmag (id go with epsom salt, as she is in flower and most calmag’s are nitrogen heavy. Epsom salt is pure magnesium… well not pure but pure for plant growing purposes).


Then based on what you guys said and my own history of events and journaling, I’ll bet my money on ph… maybe?

My medium as follows:

-Coco coir 30%/cocoloco 45%/Perlite 25% mix (cocoloco and perlite on top, coco coir and perlite on bottom)
-Worm castings on the bottom, mixed in the coco coir

  • Nature’s living soil - auto flower mix in (I prepped for 2 7 gallon bags) and they went into the cocoloco half
    -Mycorrhizal Fungi, Recharge, and Diatomaceous earth throughout each part

My water… typically my city’s tap is a 6.5 ish. I know about ph’ing my water and checking the runoff… so this may be chucked up to not doing it. On purpose… kinda? So for the first few grows of my life, i was measuring thing down to a T, and that included Ph’ing my water. My grow buddy was like, man, you’re doing too much. Especially with the ph’ing thing. So, i put it to a test: stop ph’ing my water and see what happens.

And its been good guys! But i also chuck it up to my research and my willingness to try new methods and nutes. Speaking of which, I have only watered.

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But, I also am more lax with my growing too… I spend less time in the tent, and that’s great for me. But am I truly neglecting my plants’ ph? I eyeball ti make sure I’m not leading them to destruction, and my grows has gotten better each time I plant. And this is my first time with autos so im… now freaking out lol.

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Your grow buddy needs to take a backseat. If I only chose one thing of all of the things I control at least on an indoor grow, it would be to always pH my water. And an occasional run off check to see what’s coming out, but usually I only do this when I see something I don’t like.


This :point_up_2:t5::point_up_2:t5:

No offense to the friend. But to test that theory, start him up a plant. And yall grow simultaneously. At harvest judge by weight, taste, potency, and if he even finishes or not :joy::joy:


500 years later

Here’s the plants after many weeks. I did get my ph in check when you guys told me. They’re at day 62.

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