Hey there Dr_GrThumb , yeah so basically FFOF Soil is "potting soil" except there's actually no soil in it. If you look at the ingredients it's actually Peat Moss. Peat Moss is "mined" in marsh lands , it's a sort of unsustainable aternative to coco that holds water for longer, so it's actually a soil LESS medium... strange but true i've seen it a thousand times, even made the same 'mistake' myself. So what happened is the amended peat moss was a bit too hot for the plant, hence the burnt tips, also it lacked micro nutrients , hence some of the discoloration, it holds water for longer hence some challenges to get the watering right. The good news is you're adding nutrients, careful on the NPK, keep feeding micro like it's a soil less medium , you might want to switch your additives like B52 and voodoo juice out and replace with humic or fluvic acid once you reach flower , but appart from that, the problem will fix itself now that you know about it. Hope this helps ! 🚀