My plant is 2.5 week old. Its about 10 northern light auto growing under hps 600w light in 5 by 5 feet grow tent. The temperature in the tent is about 25-28 c and about 40 rh. The light cycle was 18/6 but i changed to 20/4 cycle now. The light is place about 3 feet above the plants. There are two fans in the tent. My problem is that the leaves of my plant have yellow spot and some of the tip are burned. And the end of leaves are curling up slightly. I does water the plant every other day. But some of my plants do look healthy. Any advice or suggestion on what to do ?