Some growers (I am one of them) believe in feeding the veg ferts for the first two weeks or so of flowering and then switching to flowering ferts.

And I agree with just flipping them to 12/12.
Fencewalker Reviewed by Fencewalker on . about to flower, have some ?'s my plants have been in veg for about 2 months and are between a foot and some inches to about 3 feet. first do i need to gradually switch to 12/12 or just flip it, second what do i need to do to switch from veg nutes to flowering nutes? i have terra vega for veg and terra cannes for flowering, do i need to gradually introduce the flowering nutes or just mix as directed? i think thats it for now. Rating: 5