Ethos purple majik R1

Lots of just ph water. In flowering 6.3 ph when done replace nutrition. You should always have 20 to 30 percent run off. Especially in coco. It needs to stay 90 to 100 percent saturated. My first guess is you were feeding without run off. Run off washes out the old chemicals and salts that raise your ppm and will cause havoc with your ph if it has not yet.