Baby IRN weight

[MilesBird]

I was curious about when my bird should stop gaining weight. he is 6 1/2 months old and after a month of solid weighing he started gaining weight. Is this normal or do i need to reevaluate his diet. another question i have is about portions. This is my first bird and im never sure if im feeding him enough or too much and i cant find someplace that will tell me.