Veg NPK Ratios 50%-15%-35%
Flower NPK Ratios 25%-25%-50%
Now this is just a general suggestion and only pertains to SOIL grows INDOORS..
But yes, your plants will always need some NP and K all the time... the only time to deprive it of N is the last 4 weeks of flower... no nutes at all for the last 2 weeks.