Diagnosing the issue

[Vlada]

Problem: leaves turning colorful and perhaps will yellow

Medium/grow method: BioBiz Lightmix

Feed: and supplements used: Biotabs with Silicium Flash, water only method (not realy as I jusd added extra Silicium Flash)

water source: bottled water

Strain/age: Gorila Cookies auto FB, 6 weeks old

light used: Migro Aray 120 at 32cm distance (17cm is recomended but my grow pace is slimer (44 × 73cm / 60×60 is recomended)

Climate: lights on 25-27C. Lights off 18-20C

Additional info: Problem started after adding extra Silicium Flash ( 4 days ago) and night temps dropping to 18C. I am suspicious of light stress as well.
Was planing to start PK 5-8 feed

link to current grow:

https://www.autoflower.org/threads/gorilla-cookies-with-biotabs.81537/page-2

 

[MaskedPlants]

I'm a noob myself but from what I can see it looks like light stress. Notice how the leaves closest to the light are 'praying' and changing color, my guess would they are being stressed.
What's your current humidity in the tent by the way?

 

[Duceduck]

I'm no expert and have my own issues too but from the picture and this link, seems like light stress. Although, there are some towards the bottom which may indicate something else going on too.

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[Vlada]

@MaskedPlants @Duceduck
Thank you very much guys!
I am also suspicious of light stress, it could be that those phenos are a bit sensitive

 

[low_and_slow]

What's the pH of your runoff?

Silica products usually send pH sky high...

 

[Vlada]

What's the pH of your runoff?

Silica products usually send pH sky high...

No idea as I dont have ph meter, not much of use in organic grow.
But I tend to agree that it could be either ph lockout because of silicium flash and/or phosphor defficiency. Or it is Molybdenum in which case it is game over for that plant.

https://www.autoflower.org/threads/...-to-include-other-issues-as-well.43164/page-2

Anyway, I did partialy flash with 7.5l of bottled water (all what I had) and after added full PK 5-8 dose in 1 5L water but the most of it run out.
I see some development in flowers which didnt seem to grow at all last few days.
I will do second part of flashing today with the same dose od PK 5-8. And then we see.
I also lowered the light closer to the plants, I doubt it is light stress after all. Beside that plant is suplied with CO2 boost kit just in case light is indeed too strong. Two plants that are grown under CO2 are more progresive with flowering compared to the same age same genetics plant without CO2 supply. So it could be phosphor defficiency due to any reason, like ph lockout or simple low levels of phosphor.

 

[Arthur]

Checking the pH of soil runoff is pretty much worthless, that works in coco.
But... expecting an "organic" run to be able to maintain pH in small containers is asking too much as well. If this plant was in my tent, I'd start with a slurry test to get an actual in the rootzone pH. From there, issues can be adressed.

Organic or not, a pH pen is a great tool to have on hand when issues arise.

 

[automan2]

Appears to me there's a combination of issues...light stress and some lockout. Controlling what's going in, either thru roots and thru leaves is important. Light stress is remedied in light distance but the root uptake of needed nutrients is a bit more work at 6 weeks of age....
Myself being an organic grower...light mix and associated nutes, I always ph whatever goes in...and never feed to run off....If your plants are getting the right nutrients, they'll likely be more resistant to light stress or other 'stunting' factors....

 

[Arthur]

I could be wrong, but biotabs are time release.
If so, flushing can make your situation worse as your releasing more nutes with more water. Flushing, again, works fantastic with coco, flush and reset to good #s.
In soil it's an absolute last resort.

 

[low_and_slow]

I could be wrong, but biotabs are time release.
If so, flushing can make your situation worse as your releasing more nutes with more water. Flushing, again, works fantastic with coco, flush and reset to good #s.
In soil it's an absolute last resort.

Awesome point, flushing when there are slow release ferts in the medium is a roll of the dice...