I have never added any nutrients, I was under the understanding that i didnt need to flush if i didnt use anything except tap water for watering.It looks like maybe a nutrient or pH issue, perhaps lockout. Have you ever flushed it since you planted? If not I would flush with some type of flushing agent and feed with just water(no nutes) for a day or so then restart watering with lite nutes. Hope this helps.