PharmaZanswered grow question 1mo ago If you’re growing in hydro then yes they are worth it as you can reduce N and increase P/K
Anyone who says otherwise has never grown in Hydro or is happy with skinny airy loose weak tasting buds…
If in soil then your inputs and type of soil will regulate the NPK through the soil food web.
N - mainly for growth
P - mainly for early-mid flower
k - mainly for mid-late flower
The plant uses all nutrients at all stages of life, the above reference is a guide of where most is used.