When I get stumped I just flush everything really well to get rid of any salts building up. Didn't always solve anything but... If in Coco must flush with a weak nute mix
Yeah it's nutrient film technique. I have flushed the system twice now for 24 hours, no change. I gave her a foliar spray of King Kola (I use Emerald Harvest nutes) yesterday. Haven't checked yet today if it helped or not. My buddy gave me some Monster Bloom 0-50-30 so we will see if that does the trick. I'm fairly certain it's a P deficiency though, given the yellow leaves all over, with red veins. I just don't know why it's only one plant. They are all the same strain, the other 11 plants look iconically healthy. I'm wondering if the roots may be getting bound up in the channel and not getting enough water and nutes. The girl in front of her in the channel is off the charts. Huge 2 1/2 inch stalk and probably going to produce over 2lbs. Possible her roots are kicking the other roots out? Maybe I should add a drip line to her port?