Definitely not a waste of money. I started using boost and pk 13/14 and have seen great results. I have noticed that in addition to more yield and larger trichomes it also speeds up flowering. My purple kush usually start showing purple color at week 8 and are all purple by the end of week 9. I am in week 7 right now and 75% of my plants are purple and are huge, dense, and more fragrant than when I was using big bud from advanced nutrients. I start using it in day one of flower at 8ml per gallon. In weeks 4-6 I increase the dosage from 8ml to 16ml.