hi marcellas my rule of thumb is i pull back on my top buds and when i see mold the top gets harvested a lot were allready done before this bad off and on weather set in but the lower branches get better air flow from my fans at night on the few i had to take the tops off and seem to be able to go all the way this way and it seems if they are molding they are ready anyway in most cases after mid august to the middle of september depending on strains except for my hazes and pure sativas i only feed once a week with ferts this seems to help a lot and speed the slowones to flower faster and i do not ever have to flush if i stop nutes for 10 days and just use water but i grow in containers so it is a lot easier to have control of the situation when its bad they stay on the back porch with a fan i also always grow fast and slow plants so if there is a bad year like this has been i am asured of plenty to go around and as they get done i get more space and better airflow for the sativas on those bad days ahead in november and sometimes even december if i got a real slow one aloha classic seeds