should i add bio pk? “week 2” of flower (Bio tabs grow)

Depends completely on how much P/K you already add. It's not foie gras. You can't force feed it. It's not about more, it is about the right amount. This varies for all sorts of reasons from your environment, to the ratio of concentrations of your nutrients provided. If you add more and get symptoms, don't be afraid to dial back. It may even take weeks to present itself. Keep track of how you feed over time and it can help grealty when making adjustments to your process the next cycle. It's only difficult if you work top-down (inductive reasoning). You focus on some bro science like "use pk booster" even though it's more complicated than that, those growers rarely can admit that it's wrong even if the canopy is burnt to shit, lol. so, Learn the symptoms for p and k toxicities. (leaf symptom charts aplenty). Learn what they potentially lock out (mulder's chart) and then also those symptoms. this stuff really is monkey-see, monkey-do level of difficulty. Then you are prepared to make adjustments based on evidence... more is not always better. rate of use vs rate of provision. If you find an upper limit, back off and that reduced level probably work well next time too. I feed same levels of P/K the entire grow and still do fine relative to ambient co2 ceiling on yield. the plant relies on getting something like 60% of p and k from 'active transport' vs simply diffusing into roots. So, the plant sends out carrier molecules to grab it on demand - must have some sort of feedback system at play. So, adding "more than what is useful" just means it's either building up or draining out with runoff and wasting money.