well i am no expert but i would say overwatering , you havent got tip burn so i doubt if its nutrients. the three leaves are a bit puzzling ...i had a purple mac do that last year and that was under a LOT of stress, mainly cold and lack of light and gale force winds.
small plastic pot doesnt help ...i sacrificed one last year to look at my roots and the middle part of the soil was HOT . i use pots designed for pond plants, good airflow and drainage. I would snip off thos damaged leaves so the plants doesnt waste any energy trying to fix them.

canabless said:

View attachment 2352862

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IS this hydro, organic? What do u use, whats the ph, temp, rh like?

weed4we said:

IS this hydro, organic? What do u use, whats the ph, temp, rh like?

Click to expand...

Soil I use
pH between 6.5-7
rh?
I use Fox farm nutrients

Consider this, the plant is showing some stress. Is that pot plastic, does it have good drainage, does it sit in run off is does it drain away. How often do you water, so you water till 10% run off or no run off. Soil looks dry. What ppm are you using. Do you ph after mixing, what is the ph going in compared to what is comming out. What is in your "soil", is it ammended? Be sure to use nutrients as instructed.
Do you have a picture of entire plant?