might be your aro is adult already, feeding it that way is fine, i feed mine once a day, at times i skip meals, imo thats a good practice cause in the wild they don't get to eat too often
I feed all my fishes every day, except for my TSNxRTC... And my aro used to eat like this before he passed on. Even if I wanted, I wouldn't be able to NOT feed it because he used to eat pellets and flakes just like my other fishes, not only his food.