please..i need some help. i grow some big bang autoflowers in plagron all mix..20 liter pots..they are from 18/12 2013. i feed them only rain water. the light is 600watt and it is 75 cm away on 24/0. temp is 24-26. i need a little help,the leaves is twisting in the top and some got rust color.. what am i doing wrong? please help me..