lets see.. my aro eats whatever everyone else in the tank is eating that night.. frozen krill, market shrimp, catfish nuggets, chicken breast, turkey thigh meat, i'm sure there is more, my mind went blank when i got there..
haha. i fed my aro in japan small frogs cause i saw them do it with asian aros at a local shop. at first they looked at them like wtf are you doing in here and i had to starve them before they ate them...
i thaw out the things like chicken breasts and turkey thighs that need to be cut up and the fat removed. but market shrimp and krill is only run under cool water for a couple minutes to get the ice off the outside and make it easier to break apart. And i've found that catfish nuggets are much easier to cut into bite sized pieces if it's still partially frozen.
Its not always the food that is to blame. Oscars are very messy feeders and as you may have noticed when they munch away on their pellets small particles of the pellet exit through the gills and it is those particles that cause the water pollution. Oscars do this with all pellets so it doesn't hurt to feed wet food and do more water changes.