Sorry not so experienced with organic grow as well as do not know your soil, but to me it looks very dry. When you run not organic soil you should water to have at least 10% runoff and than let it dry out completely before next watering. If you want to have regular runoff you need to use quite a lot of water. Yours seems to me like you are adding every day only small amount of water. Not sure about organic but its soil as soil so I think it is pretty the same when you use some nuts - need some runoff. You treat your soil like a coco, so maybe it could also be root issues. I would just try to water it little bit more to have some runoff and than let it dry out and see what will happen with the plant. If it will getting worse, on the net is written - wood ash or seaweed meal are rich in potasium, but check it also by yourself, maybe I went somewhere wrong!