NEVER feed coco plain water. That's like feeding a gremlin after midnight.
You appear to be at the start of flower. If you are feeding a multi-part nutrient then cut back on the veg part. What level are you feeding at now in ppm or EC? It's hard to tell with pictures with the lights on, but the leaves seem super dark green and the tips curling down indicating a nitrogen toxicity or excess. Cutting down on the veg part of those nutrients will reduce the nitrogen and overall EC of the feed. Good luck.