Athosanswered grow question 6 years ago If you are going to use coco, you have to use an EC/PPM meter, else you are going to be guessing. Without that information I can only guess, but it looks like a mix of nute lockout, magnesium by the looks of it, and nutrient burn. Get a meter and feed 0.5 to 0.6 EC, primarily cal mag and some veg nutes.