TheJimsterness

Just out of curiousity, could i stock anything else(invertebrates, fish, hamster with a scuba device) with an oscar in a 55g? I just don't want him to be lonely. I've been looking at crabs, but they need brackish water. Could i maybe throw them in some brackish water on weekends in a separate tank, then put them back in the main tank for weekends. Maybe I'm thinking too much about this...

JakeTeque

I would think some Bala Sharks would be okay, or some other peaceful fish that don't produce a lot of bioload. Even though I have 2 Oscars and a Firemouth in 1 55Gal I am going to have to upgrade when they get larger, But I am able to keep ammonia and nitrate at 0ppm. Depends on what you plan to do when your Oscar gets too large for that tank. I would think two or three sharks with an oscar would be fine for a long time.

PetSmart

I have an oscar with a big green severum ... and a jack dempsey.

kamakasi

i would say a balck ghost knife fish would go great as long as you put some plants in the tank and some hiding places you should be fine.