hey all i need some help im following the FF nute schedule and im almost going into 4 weeks of veg and gonna be switching over, now should i flush before going to 12/12 ? and how long do i let the 4th week of feed sit into the soil before flushin into 12/12 and then into the 1st week of flowering nutes?? im abit confused right now on how to go about things... thanks for the help