about 150 ml or so every 3 days. NO nutes yet. Unsure of the PH. Its nestle pure life bottled water. I am using 2 40 watt, 6500k cfl about 3-4 inches away and a third 42 watt 6700k about 6 inches away. The temp stays around 72-75 and am unsure of humidity. The black is spreading at an ever increasing rate. They seem to be getting worse and worse. but only the top set of leaves.