Yellowish leafs

No..........issues may be due to excess salts in your re-used soil mix. Tip burn on new leaves can be a sign of over feeding, damaged lower leaves are indicating soil problems. Foliar feeding twice a day is not useful either.

Parameters for growth look fine, hmmm, oxygen depreviation of rootzones, oxygen itself is kinda like a nutrient in that it needs to exist in the rootzones in order for the plant to perform photosynthesis. Your soil has no perlite or anything thay would give it the air pockets its needs, soil looks very grainy and fine meaning top watering could compress the soil especially if you blanket feed. Leaves look wrinkled and fat, wayer it building up in leaf as it's not being released efficiently through transpiration. Many reasons this could happen but if I had to guess I'd say it's a breakdown in water movement. Big plastic pots with little to no oxygen pockets to play with. Right off bat you need a pH possibly a ec reading to get an idea of where she sits, worst thing you can do is add more salt minerals until you know it's not ph or rh. When transpiration becomes crippled wayer doesn't cycle if it doesnt move from the plastic pot it will stagnate causing eventual salt build up if you continue to feed, what goes in must come out. More moisture is going in than is going out, most likey due to a breakdown in water movement. If you had a super dry arid environment and needed a way of retaining moisture plastic would be a option. You run 80F+ in a pot that's unable to breathe. Moisture will only uptake or evaporate, evaporation is not a option for 90% of your pot. This is more critical in warmer climates because at higher temperatures water holds less dissolved oxygen (DO).

Hi sieht mir nach zu viel aus, wenn dein PH wert aus dem Tagebuch 6.8 stimmt und das auch der runoff ist bist die gerade so am oberen Bereich des guten und könnte schon richtung schlecht werden. Kontrolliere den runoff auf PH und EC der letztere solte nicht über 2 liegen sonst kommt eventuel zur überdüngung oder Blockade. Denk daran das was du an den Blätter siehst ist vor einigen Tagen im Boden passiert. Stickstoff mangel ist es aber definitiv nicht. Wenn es ein Mangel sein kann dan CalMag oder Phosphor. Aber überprüfe zu erst die oberen Werte bevor du mehr dünger gibst. CalMag kannst du aber trotzdem hinzufügen als vorsorge in kleiner dosis. Viel erfolg.

The newer growth looks fine to me.They're best withdry cycles but don't oush it too much as you will get some dry back on the roots which you obviously dont want.