Hello! I am having some issues with a few cannabis plants here. A few plants have shown signs of purplish ridges on leaves that eventually turn into full blown purple associated with pale green leaves. At first I thought this was do to a few cold nights, however as the issue progresses I fear for my plants. I've adjusted P.H because my run off was 5.3-5.6. It has now been 2 weeks and the problem only progresses. My runoff is now at 6.3 where I had originally wanted it. Any help would be appreciated!