Betta fish feed criteria directly depend on its size attribute. Betta fish needs to feed twice a day, once at night and once in the morning. Feeding them twice a day is important because some bettas are larger in size and they opt to feed more. Small and young fishes maybe feed only one time a day as per requirements. Babies should also need to be feed twice times a day. The correct portion of food for your betta fish is about 1.8 grams. This is an estimate not exact. It varies according to the size of your fish.