Read this. It would be great if it was genetics which it could be but never take out the possibility of a deficiency? What ph is the water your using? What about mulch? Have you read about that? Without a balanced ph system plants can lockout and not absorb proper nutes. And stems are great indictators of genétics but usually they go fro. Stem and vein as well as l3af. When u say waves of purple...sounds like it could be phosphorus-deficiency. The purple stops before the veins. ..which [URL="https://www.------------.com/phosphorus-deficiency-cannabis"[/URL]