I only feed mine once per day, and they have been healthy for years. I think that general advice is to feed as much as they eat in two or three minutes and remove the rest. I really like the Omega One mini pellets. They float only momentarily before sinking, which is helpful for goldfish with telescope eyes. I have also used Hikari, and like that too, but prefer Omega One. Both will let water remain very clear.Somervell: I cut down from three feedings a day to two, so it is certainly possible. And when people say "a pinch of food" I feel like the pinch is in the eye of the beholder. I wish it was more specific lol
As to the biowheel, Penguin makes good HOB filters. I have used them with goldfish successfully. Right now, I have a H.O.T. magnum ( same basic principle-- also a Marineland product) and it works very well on a large tank.