Honestly this is one of my biggest complaints with AN.. Why three different product names for what is all essentially P-K booster with different formulas.... When I'm using overdrive I will use it exactly as described by manufacturer... I might go a bit lighter on it then what manufacturer says as it still has nitrogen in it. I use approx. 1/ml per litre all the way up until last week before flush so if you have like 12 week flowering haze you would wanna keep running overdrive for like 4-5 weeks or extend your use of big bud.. Advanced Nutrients has the stupidest Nutrient Schedules..