What causes the hairs on the roots to die? If it does is whole root dead? I grow in all inorganic media. Water daily. Fertilize weekly. Peter's excel15-5-15 at 300ppm. Fairly high light 3000 foot candles. Fan on them at all times. Grown in a greenhouse in florida. They do well for months then roots just start dying. Or/And get brown spots on leaves near base. They aren't soft like erwina. One has interior leaf turning brown. No odor like phytophthora. No ring like fusarium. Why?