Beautiful tank. I have 2 oscars in a 125 myself. 1 of them was a rescue, the other i have had since he was 1 inch long. He's now about 2.5 years old and he is a little over 13 inches. I feed Hichari gold pellets (with some krill and massivore pellets as a treat every now and then). Oscars are quite beautiful in my opinion and have lots of personality. I have never fed mine live food, which I think makes him less aggressive. I have been able to add much smaller fish to the tank (a small pleco and a 1.5 inch nicaraguan cichlid-both of which are now larger) and he has never had a problem with them (eating them).