Mean muggin
It might have less to do with EC than it has to do with intervals and drybacks. What sort of intervals are you irrigating with in that setup? Also how often are you dumping your res?
They are getting fed 4 times a day to runoff. The slabs are staying on the drier side, which is what I was shooting for. Anytime they get soggy they get root issues. I think the heat plus the lower moisture level is bombarding them with nutrients. They are also the shortest plants, so they aren't getting as much light and probably not processing the nutrients as efficiently as the taller plants. That's my guess anyway.
I don't grow in rockwool, but I think I would want to feed closer to 6x a day if I did.
Could be, I have a strain like that I'm growing for the first time right now, along with other strains. Didn't you say that you have a different row of the same strain doing fine though? What's the difference with the rows?
It's drain to waste and I'm using up the res daily between two rooms, so I doubt that's a problem.
I think both rows are affected, but only the one row has progressed to burnt margins. That's why I would assume it was a root issue, but they look healthy.
Yeah, I have to change my intervals from winter to summer as well. My guess is the drybacks are just a bit too much and causing the burn, not the feed EC.
