Hey Pipe,
I'm growing in FFOF soil, my PH is around 6.8 according to the cheap 4 in 1 meter I have. I used FF nutes for veg but ran out of them when it came time to flower and switched to JAcks Classic bloom.But these spots showed up before I gave them any of the Jacks. I do have a small amount of Fungus gnats but I have something for that now that I will use tomorrow.
I have some leaf clawing going on that started as soon as I transplanted from 1 gal to 3 gal that has never gone away, dont know what that is about.
Since I gave them such a small amount of nutes I didnt think it would be nute burn, but I do have some burnt tips along with the yellow, so I flushed 2 days ago and am waiting for them to dry.
I really liked the Columbian skies but grw it under bad conditions(CFL) and got small yeild, about 1 z per plant. But I thought the potancy was real good witout the couch lock effect. I find myself smiling alot when I smoke it. I talked to a guy who grew it outdoors and got 12 z's per plant but said the the potancy was only ok, each to his own. I have 1 clone struggling for life right now and it looks like it might make it, but I also still have about 6 of the seeds still so maybe I will pop them after the next few go arounds.I have a better system now so if the clone makes it I will see how it does under a couple 400 hps.