I am a relative newb to growing. I've been growing successfully for about a year. However, I can not seem to find an answer to this seeming anomaly: My plants have recently begun to grow two stems at each side of a single node. The top growth is a stem that continues to grow many nodes and the growth below is a single fan leaf. Both growths connect at the same spot on the main stem. Often the lower leaf has a purple stem and the top branch is normal green. My question is "is this normal?" I am growing with DWC and under high end grow LEDs. Environmentally ideal conditions (~75 Fahrenheit, ~30-40% humidity, tons of airflow.) These are otherwise very healthy plants. Any thoughts?