Good you've been flushing so hopefully you have flushed out most of the grow nutes,i prefer to actually,at this stage,re-pot into the larger 5 gallon pots with a fresh medium,i use soil,perlite,lime,vermiculite and coco can also be used.
The vermiculite stores nutes the way perlite stores water so thats why i prefer to just totally repot so the vermiculite will now store your bud bloom and once you repot prior to flowering you need not do it again,even when you change from bud bloom to bud booster.
I started doing this cos i found that when i didnt repot prior to flowering the nutes were getting mixed and i was getting a concrete type build up and nute lock out so i started repotting before12/12 and never had the problem since.However JD has shown you the way and the book he quotes from is like the MJ bible,i also own some Cervantes books and he truly knows his stuff.BTW,you can pre determine sex without putting them under 12/12(and no you wont need to veg for months)just look for little signs like male pre flowers,white hairs,amongst others signs.Happy Growing:joint: