Need assistance on a CBG Auto plant

Been growing for a couple years now, messed with autos a couple times, but i have a lot of back pain and wanted to try cannabiogen’s CBG Auto. Plant took off great, did some LST and it bushed out to the point I had to break the rule I read everywhere and trim it a little. Plant has about 2 weeks left but for about the last 2 weeks it has been getting a progressive leaf thing that I thought would fix with Cal/mag like my photo period plants have, but once the leaves get to a certain point they curl and crumble at the top, bottom and middle. PPM’s did get up to 2500 in week 5 so I put 1 1/2 gallons of PH’d water through it, it was back to 1350, but no change. This thing was doing so well, I don’t want to lose her now. Any suggestions?

Growing in FFOF, under a Mars Hydro SP250 at about 15 inches above plant using Advanced Nutrients and an 18/6 light cycle.

Have you done a flush and if so did you take runoff numbers? PH and TDS both. That will likely tell the story: FF soil recommends periodic flushing to get rid of excess salt buildup. A flushing agent like Florakleen or Sledgehammer will help too.

FYI it looks like you have more than two weeks to go.