hey everyone well i'm really stuck with this problem and don'nt know what to do! desperate need of assistance my master kush plants are 20 days old now.. started from seedlings. ive noticed curling down and yellowin/burning of the tips but i havnt added any nutes? they are being grown in rainforest aeroponics with 400 watt MH . i have a fan circulating air and PH is about 5.5 i really need hellp because im really hoping to get clones out of these plants much thanks for any help