I bought a clone a few days ago that was about 18 inches tall and looked real healthy. A day or two later some of the leaves started drying out and curling up. They are in soil and the PH of the water they have been getting is 6.5. They are under a 1000W light and the temp is good. I have read that it might be mag deficiency but am not sure. There is very little discoloration in the drying leaves just a little browning once they are very dry.