Does this look like potassium deficiency?

[GrassTown]

In organic living soil, pH of 6.7 in the pot. Not happening to any of the plants around her. Just looking for inputs.

 

[mysticepipedon]

Yes, it does look like K deficiency, BUT it may not be.

Do all the lower leaves have the symptom, and it gradually disappears on the leaves above it? If so, it probably is a K problem, though it may be lockout rather than a deficiency.

If all the lower leaves do not have the symptom, but only leaves getting direct light from your LEDs, it's light burn.

I can't tell from your pics which it is.

 

[MEGA956]

Purple stems aren't a good sign, best of luck to you.

 

[GrassTown]

Yes, it does look like K deficiency, BUT it may not be.

Do all the lower leaves have the symptom, and it gradually disappears on the leaves above it? If so, it probably is a K problem, though it may be lockout rather than a deficiency.

If all the lower leaves do not have the symptom, but only leaves getting direct light from your LEDs, it's light burn.

I can't tell from your pics which it is.

It is mainly on lower, upper leaves aren’t as bad but seem rubbery. Could be a lockout than.

 

[mysticepipedon]

Sounds like nutrient problems. @MEGA956 pointed out the purple stems. Any possibility you over did it with calcium? That could lockout P, K and Mg, as well as others.