The ends of some of the leaves on one of my plants are browning and have become very brittle. The leaves shown are the ones where the effect is most noticable, it is present only to a minor extent elsewhere. That plant is Nirvana's "Full Moon" - Sativa dominant. The other plants, including the other Full Moon I have are perfectly happy. This one was fine on thursday when I went away for the weekend. Soil grow. It is at start of week 6 of flowering. Have been growing 6 plants (2x each Venus Flytrap, Blue Mystic, Full Moon) in a closet under 400w HPS and 65w CFL (65w/200w equiv). Each plant is now drinking 3/4ths of a gal of water containing 2 tsp/gal of 15:30:15 fertilizer twice a week. PH of runoff after watering with plain water was 6.2 It looks like it could be a phosphorus deficiency, but they should be getting plenty of that, shouldn't they? This is my second grow (first one had no issues like this), so i don't have much experience with plant problems. I was wondering if maybe the problem was from not loosening the pipecleaners I was using for LSTing earlier; the branch with the most symptoms had a significant groove where the pipecleaner i used to hold it down for LST was, but i don't know if that could produce this effect. Thanks in advance everyone!