That's the hydro formula for bloom. Soil locks up some of the Phosphorus so the Pureblend Pro bloom formula for soil has more P (1.5-4-5). Cannabis is mostly a Potassium hog until the ripening stage. This is why they recommend ripening hydro plants with the soil formula.
Pepper Reviewed by Pepper on . questions about Pure Blend Pro Bloom when reading the N-P-K rating... (2.5-2-5) why is the Nitrogen higher then the Phosphorus? Rating: 5