Sollte ich schon anfangen Calmag zu geben?

This is a bit puzzling to me.... I almost want to say it has nothing to do with your soil, your conditions, your nutes... I'm thinking you have a problem with some insect or other... and which insect it is doesn't really matter (it's not a leaf CHEWER, but a leaf SUCKER)... Have you noticed anything of the sort? To be honest, whenever I've had insect problems, I've never actually seen the little bastards - only seen the damage they've left behind... I would grab some Dr. Zymes Eliminator (or Spinosad) and use it as directed spraying tops and bottoms of all leaves just before lights out... Because there really IS no indication it's anything else... Both products, btw, are organic and can be used at any stage of the plant's life cycle right up to harvest if need be... always good to have on hand! Good luck!