how much fluctation in PH is bad? unless my meter is off.. im PHing between 5.9 - 6.4. can that difference cause this/strees/burn?
im in coco, feeding about 670ppm this week
i think the whole is just die thru..
someone suggested this is potassium deficiency. it could be.. they are at the start of flower.
I do use a PH pen.. that could be off? but to not get potassium i gotta go down to below 5.5, no? or above 7.x