Possible Leaf septoria?

[bouillabaisse]

Only occurring on the tops of one of my autos (unknown genetics). I've sprayed it with a copper fungicide before any buds came in, but the problem still persists. I've read that septoria starts at the bottom of the plant and works up, so it seems weird only the top of the plant is affected. Also seems to only spread to leaves in the immediate radius of the dying ones. Any ideas?

Feeding - coast of Maine organic plant food, 2ml per gal of grow big, 1ml per gal of gringo rasta cal mag, and a tiny bit of molasses every other watering.

Light - 1200w king LED

Medium - ocean forest, 3 gal smart pots

Temp - 77 - 81 lights on, 68 to 70 off

RH - 50 - 60%

 

[Mañ'O'Green]

Looks like potassium deficiency but................

Please fill in this form: (copy and paste part is below, this first one tell what specifically to include)

-Problem: (brief description)
-Medium/grow method: soil; soilless-- coco, or peat based like Promix, etc. (please provide the actual product name); DWC, NFT, etc.
-Feed and supplements used: include brand, dosage/strength, frequency of feeding and watering (alone); method-- by hand, drippers, rercirc' or drain-to-waste,... N-P-K #'s too if you can!
-Water source: RO/DI; tap- dechlorinated-?..... EC or TDS reading; pH (don't bother with this on RO/DI, do bother with TDS/EC though to confirm it's working well enough)
-Strain and age
-Climate: night and day ambient T and RH%; res' temperatures; any extremes in T/RH% exposure
- Light used: HID, LED, COB, combo of,... wattage; light cycle hours (20/4, 18/6 , etc.); distance to tops....
-Additional info: PH in the root zone. How long have the plants been affected?...How fast did symptoms appear?... Anything else you think might be relevant..

--Pictures including WHOLE PLANT PICS, and troubled leaves.. use normal light or flash as other light sources ruin color rendering, critical for diagnostics!

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(copy and paste)-->

Problem:

Medium/grow method:

Feed: and supplements used:

water source:

Strain/age:

light used:

Climate:

Additional info: