Ya man some pics would be good.. ya best way to see if ya have light leaks is to stay in the room when lights off. dis way u will know for sure.. i use tomato feed for flower and it works brillant.. just start off wit quater strenth nuts and work your way up from there.. this way gets the plants used to the feed witout burning them.. i use 2 ml per litre but just cheque the lable on your feed could be stronger stuff than mine. when ya water your plant give it a good soaking and make sure the soil drys out between waterings.. overwatering causes many problems too..