Okay- that 6.8 is DEFINITELY your runoff number and not the pH of the fertilizer you are putting IN?
GH is buffered for hydro. Earth Juice is definitely acidic as well. Lockouts occur in soil when the pH is too low or too high.
Also you are running soft water and calcium deficiency is a potential culprit. That's easy; add calmag to 250ppm before adding other nutes, and then bring your fertilizer solution pH to 6.9.
Is there any chance that there is sodium in your water? The damage looks consistent with pH imbalance and salts buildup locking out needed nutes.