General hydro BLOOM, MICRO, GROW
Yeah you have no need whatsoever for a pk boost. Your grow, micro, bloom is added in different ratios to boost pk. If you adjust your grow micro bloom to flower ratios and add a PK you will create issues. I see this very often.
With your nutrients imo when you switch to transition ratio stay there for the duration if the grow. Pk is a snake oil kind of. P is accumulated so should be given in veg and stretch then stopped. K is most used late flower. And nitrogen is needed pretty significantly until after swelling much like calcium.
I'm going to leave it simple like that although there are more advanced feeding schedules but keep it simple and you will have better results than if you start adding a bunch of things. I promise you this.
The only way it would be worth adding any PK boost is if it contained a PGR like triacantonal. In that case you would stay with veg ratio base nutes and then add the PK. As you would do if you added koolbloom. But there is no point when you can just change your 3 part ratios to end up with the same thing.
Ratios are extremely important and the way marketing is on PK is absolutely bullshit... to be honest.
I am absolutely open to anyone on a discussion about this. I'm not trying to knock anyone for using them. Especially if your vase nutrient does not have the ability to change your NPK ratios.
Tldr: save your money for upgrades all you need is the 3 part. If you want to add anything to it silica and you will have good results. Take the time to learn about NPK ratios and understand the cannabis industry is full of bullshit in every area to seperate you from your money.... especially nutrients