milkman407;520338; said:zzoscars can be bullys, untill the outher fish fights back that is. They grow very fast i bought a baby oscar ( he was the size of a dime maybe a lil bigger) 3 weeks later hes about 3" Oscars get around 12-16" so they will need a 75gallon for just one. They are also tank busters and will ram the glass some times. They will eat anything and poop alot. They are very messy so you will have to have a large bio filter. and frequent water changes is a must
i think a oscar could live in a 55 by its self. if a 75 then it could have some tank mates, but they couldnt get too big