tear-one, Check the thread two down from yours called Leaf curl problems- the claw. Your plants look just like those. Check your soil ph and report back here with what it is at.
Is that the ph of the water or the soil? The two can be very different. The more important one is what the ph of the soil is at.
Check your Feeding habits. I've had the same problem and it was due to too much N. The last time it was because my Homemade soil was too strong in the N dept. Always fixed it by reducing the N. At first sign of over fert the claw will be exhibited, if it is a mild over ferilization problem. If it's stronger then the claw will be skipped and go right into "burn" spots and disfigured leaves.
Probably a nute disorder. I'd start treating it with a good flush. Use water only, 3x volume of your soil. What nutes are you using, and how much? Make sure you obey the label on nutes, or use a ppm meter to make sure you're not giving the plants too much. I prefer to stick with all organic nutes, because it is harder to overfeed. Also, checkout the plant abuse chart at http://www.overgrowforum.com/modules.php?name=growfaq#abuse this has a lot of info and pics to help you diagnose the problem.
