I've created a very simple wick system to try and grow a couple of arugula plants.
I cut off the top of a plastic bottle, inverted it, inserted a wick,put in coco coir and the plant, and placed it on the bottom of the bottle.
Since the plants are young, I only gave them 1/4 strength of masterblend mix.
Plants are growing indoors under an HLG 4k light.
They started growing pretty well and looked good but now something has happened to the leaves, and I can't figure out what is causing it.
I've attached pictures.
Does it look like a nutrient problem? Was 1/4 strength too much? Not enough? Or could something else be causing this?
Appreciate your feedback.