Mornin Highpo...ya those white tops eh....a lot of us get those ...even Doc. I get them too. They are harmless as far as I know...it's just the chlorophyll that's bleached is all...the gland heads appear normal and I always medicate with them as usual. It appears that during bloom when the tops and certain areas of the buds are in a "hot zone" or a super concentrated area of light. It helps a bit to move them around but in the end it doesn't matter much as it doesn't affect yield or potency....just looks brutal , is all! BTW I grow like you....letting the plants come up to meet the light...makes no difference ...I still get those white tops ....and it's not always the tallest either. I have another light on the way to boost my total light getting to the buds late in bloom so I'm wondering how that will affect them....lots more light comin , so we'le see eh! Cheers eh and have an awesome day Highpo!