Join Date: Nov 2011
Location: South-central Washington State, USA
In my experience, no fish truly grows to the size of the tank it's in, especially large cichlids. Oscars can top out at around 16 inches, and while they may grow slightly smaller than that if kept in inadequate space, they'll end up deformed and unhealthy, as well as probably skittish and thus, frequently injured, as they have a habit of dashing around the tank if startled and running into decor. Keeping one in an 8x8 wouldn't work.
Look into Bolivian rams. I have a single male in one of my smaller tanks (12x12) and he's doing great. Bolivians don't have the same temperature and water quality requirements that German blue rams have, making them a little easier to keep. Plus, they're cichlids: you still get that same great personality, just packed into 2 inches of fish.
"One day...one day, this path will lead us to the White City, and the tower guard will take up the call: the Lords of Gondor have returned!"
–Boromir, The Lord Of The Rings