Maybe i stalled the one plant with too high EC on last change, seems to be moving along now, even a little more stretch last night.
I'm experimenting this flower cycle with adding a little fulvic in between res changes (none in top off) and it seems to be a miracle worker. I usually change res once a week in flower or if i see the pH dropping instead of steady or slight rise. I've experimented twice now with adding a little fulvic at this time and it's crazy, the next day the pH is back in the right direction and the EC takes a hit, it's like it instantly helps nutrient uptake.
Ph down trend (bad)
Add fulvic
Ph stable/slight rise (good)
EC lowering (good)
Growth spurt (good)
Interesting, thought i would share.