Best is follow the milk powder can different milk powder can got different scoop as in some milk powder can they put 2 to 3 scoop and others milk powder they put 4 to 5 scoop and it depends of the scoop size and also add 90 Ml of water + 3 scoop
90ml + 3 scoops. normal for it to increase in volume. if u add 80ml + 3scoops it’s under diluting