I think the edges curling up look to me to be the plants are getting too hot under the light yu have. Not too sure about yer setup but it looks like yu are runnin an HPS light. about 600w I would say from the intensity of the light in the pics. If that is the case then it is too close for those little plants to handle the intensity.:doh: yu would better serve yerself to run a lower watt metal halide for veg growth(400 or less depending on yer grow space). then use the HPS for flowering. Also yu should always place yer hand palm down over the top of the plant and feel the light on the back of yer hand. If it feels too hot to yu after a minute then it is too hot for the plants. raise it until it no longer feels too hot. also if yu are not running a fan within the grow space, get one. they need the air to circulate a plenty in the space (make em dance a little), and if yu don't have any exaust to replace the air within the grow, then yu really should get one set up so that the air in the grow doesn't get stale as that will hinder plant growth terribly

Good luck and good grow mojo to ya
