coco and using a little nutes yes not much a lot less than half recomended dosags, always ph right after
Most of my herbies freebies get coco, i prefer soil myself. I am not that good in it yet, no ph cause my water has low ppm so no buffer and ferts do that job. Try not to overwater, find the sweet spot for when they want drenching again.
I try to use run off to raise or lower my coco ec/ppm, a few waterings just water with plenty run off shows if the plants needed ferts or less. The concept that if you feed at 1ec and get 20% runoff youll maintain the coco ec at 2ec or what not rather than thinking your inputcec is your coco ec.
Plants avoiding light is transpiration, roots not sucking enough water.
I cant offer more but it should be easy to find what they are not liking