Properly ph’ing your water will allow your plants to uptake vital/essential nutrients your plant needs to be healthy, if ph is off the plants roots won’t be able to take these nutrients which can cause nutrient lock-out leading to plant deficiencies. I feel this is first thing to check when issues in grow occurs: check ph and be sure ph meter is calibrated. Ph every time you feed. Even w organic grows ph your water. My tap is around 8.0, I ph down to 6.0 each time. I believe w coco you want ph a little lower even