Two to five oscar fish can stay together. Oscar fish are social creatures, so they enjoy being in pairs or small groups.
However, oscar fish require a lot of space to thrive. A full-grown oscar typically needs a 55-gallon tank or larger. For every additional oscar fish, you need to add at least 20 gallons to the tank. If you have limited space, just stick to keeping a pair of oscar fish.
Additionally, you shouldn’t attempt to keep three oscar fish together, as two of them may bond together and dismiss the third one.
