Could have something to do with the strain, maybe a longer flowering time? If its a sativa or a haze, it'll take longer to flower. Also, I'm all for trying new grow techniques, but why would you use veg nutes in the flowering stage? Your plants look really great. I would wait until a little later in the game to start worrying about bud size.
but why would you use veg nutes in the flowering stage?.
Lovemug , I am growing with a 600 hps also but I am into my 5th week of 12/12.
I update my journal in my sig. with pics at least once a week so if you want to have a look for referance your more then welcome