The principle of nutrients in 2 or 3 parts is to be able to adjust the grow and bloom according to the phase of the plant. In veg, you put 3 ml grow / 1 ml bloom. And in flowering, you put 1 ml grow / 3 ml bloom (the dosages were just to give you an example).
Personally, I used this range and generally, I put 2 ml per liter of base water, and in flower, you add big bud..overdrive..sensizym..if you have any questions, feel free to come by, I'll be happy to answer!