I am in coco/perlite. Using RO water and adding 100ppm cal/mag, 300ppm FloraNova grow. Only one of my plants is showing the same symptoms as yours, and ALL my other plants in veg are healthy. Funny thing is it doesn't seam to be slowing the plant down much, if at all. It's been doing it for a month. It's still growing at the same pace as everything else, and new growth always looks good, but I have leaves doing exactly what yours are doing. The other weird thing that has me stumped is that it's not workign it's way up or down, it just happens on random leaves, new and old.