It looks like your leaves are showing signs of stress. If you notice the edges of the leaf blades are curled. Your high temperatures aren't helping out the situation. You may be dealing with a LVPD issue (Leaf Vapor Pressure Deficit) I would try to increase the humidity to at least 65 68% by using a cool mist humidifier in your grow space this may help lower your temps into the high 86-87 F range.http://www.just4growers.com/stream/temperature-humidity-and-c02/vapor-pressure-deficit-the-hidden-force-on-your-plants.aspx I would also try to back off your lights to 20 inches for a few days to see if those leaf blades will straighten out again. It may be a bit of light burn about to occur. Hope this helps.👍