Follow the water before you add the formula milk not after. So if you want to give 160ml, put 160ml of water then add formula milk. The water will rise due to the volume of the weight (formula powder) in the water. If you want to give 190ml of formula milk, then put 190ml of water. If you read the reading after you add the powder then it is wrong. Means your baby will be drinking more water than what is needed. Always measure water BEFORE the milk powder.
Depending on what is stated on the fm tin. so if the tin states one scoop to 30ml water and you are giving 3 scoops, then add (3x30ml) 90ml water. The volume will definitely be more than 90ml, but that’s the correct composition.
Depends on the instructions for that formula. But generally, add 160 mls of water first. Then add proportional formula.