Seeweed

7.5ph really? That's the problem.

@Superstuff, I have soft water of 60ppm, I add calMag to 200ppm, I thought it would be enough... okay, I'll try a new solution with 280ppm today, let's see how it reacts) thanks for the hint🙏

@Seeweed, In this case Nitrogen Toxicity is more likely, you can notice the end of leaves starting to droop, in claw like form. Leaf tips burning might be several things: water reservoir getting too low on water and plants getting insufficient water for one day, lights blasting too close at too high intensity, from too high EC raise. Could be any of these, but at this point im not going to start raising my feed since overdoing it might affect the quality of the end product. But thanks for bringing this up, always good to get different opinions on stuff like this ;)