Tom - your fish eats the 4.5 mm Jumo fish formula, same as what I feed my big boys.(there is no 5mm pellet)
Also - to the OP.
As you can see by my previous post, it's not about finding the LARGEST pellet so that you can feed fewer pellets to your fish. IMO & IME the 4.5mm floating pellets will be a better option vs feeding the larger 7.5mm pellets to oscars in the 8-10" range.
Lol I guess I couldn't write fast before you posted lol... So ya think the 4.5mm will be better then the 7.5mm ?? Even for when they get 12"+ the 4.5mm and 7.5mm is the same price that's about the same size I'm feeding now and the 8-10" doesn't make any mess but the smaler oscar and other's only have a little bit of mess out there gills when eating ...