Hi
@Johnnyb__blazin! You're having salt buildups in your coco. You can keep on feeding at very low EC/ppm for a few days, or give it a good flush with only plain pH'd water before going back to a reasonable feeding schedule. The first solution is the less risky one if you don't want to create any deficiency, but make sure you always have a good runoff so the medium can be purged. Hope this will help, happy growing 👊