I think the rockwool IS your problem....and you need someone to tell you what to do with it. I know it's notorious for soaking up and holding water and needs all sorts of special care.....presoaking....careful watering times..gets screwy on the ph....etc etc. As I say, I don't use it so can't help you with it....but I'm sure someone else does and would know what to do. Somewhere around here I posted something about the stuff awhile back....let me check my old posts.
Weedhound Reviewed by Weedhound on . some leaves thin, curled-upward, browning edges Hello all, I'm a newbie, on my first grow. I just switched from 24-on to 12/12 yesterday (600w HPS) , and today when the lights came on I noticed that about half my plants have varying degrees of a leaf issue that I'm unsure about. Some of the leaves have begun to curl upwards along the edges, with accompanying browning and a thin appearance. There's also a bit of yellowing on all of the plants, which I was told was signs of growth and not to worry. But this is new, and I'm concerned and Rating: 5