If I told you to pH to 6.8 then I apologize. If you look at the pH chart on the right side 6.8 locks out some of the lower nutrients. Some people like to vary their pH for max uptake, but I stick pretty close to 6.5.
Do you let your water sit out for 24 hours or so to allow for the chlorine to evaporate?
How old are the plants we are talking about. I see you only used FF trio nutrients once and at 1/4 strength. How long ago was this and how old are those plants?
They are probably getting a little hungry too!