canna boost or bloombastic?

hi im new to this site ive just flipped my 3 plant pineapple express grow into flowering this week . im not sure when to start boosting the plants? ive got canna boost canna pk 13/14 and bloombastic can any1 give me sum tips on when to boost ?

I personally don't use canna but I know a guy who does and he doesnt use the boost at all just a little pk and the boombastic he swears by it.

As I said he is a mate and its not personal experience but his results are excellent.

Mouse