nutrients... what is best

ok i have a quick question! during the veg cycle what nutes does a plant use most? im already aware Nitrogen is needed 4 leaf growth & development. im sure its vital that the roots get nutes 2 encourage vigorous root development, im just not sure if it is needing potassium or needing phosphate. if i can remember correctly phosphate is used for flower development & potassium is used for root development but i could have that backwards. if someone can let me kno it would b greatly appreciated! thanks every1

Phosphorus for flowering and young root development. Potassium is kind of like a regulator for the plant, lower amounts for veg a little higher for flowering. Magnesium is also very important at all growth stages. Fish Emulsion is a great 1 part Veg nute. 5-1-1