@PadawanWarrior Ehm sorry didn't cross my mind that i will offend you by mentioning you two together. My apologize. Thank you for the answer! I will leave them a couple of weeks more as suggested.
And yes they are not happy, or where not happy. I tried everything, thought it was nute burn, and it was not, thought it was heat stress, checked to see if I underwater or overwater but it was not the case, run of ph 6.2, ppm 650 at runoff is the max value i ever had and surprise surprise the thing that was killing my plants wasssssss(drumroll) excessive light. They do not like, to my surprise, lux over at 35000, or they get burned, they only like 25000-30000. after adjusting the light, the symptoms stopped advancing and got a little bit better over time. some of the damage could not be fixed unfortunately...