There are many species of fish that can live with an Oscar. South American Cichlids, Arowana, and larger members of the Barb family all make for good companions. Choose tank mates that are non-aggressive, roughly the same size as your Oscar, and can’t fit in your Oscar’s mouth.
I first started keeping Oscars about 30 years ago. Since then, many have passed through my fish room. I have kept almost every color strain on the market. Currently, I have a 180-gallon (680 liters) aquarium with a trio of Lemon Oscars. It is an aquarium full of movement, color, and character.
Can An Oscar Live With African Cichlids?
It is not recommended to mix Oscars with any African cichlids. Oscars come from South America and Malawi cichlids come from Africa. They have different requirements in terms of water parameters and Malawi cichlids are often more aggressive than Oscars.
Cichlids from Lake Malawi like to live in hard water with 7.5 to 8.5 pH whereas Oscars, who come from the softer waters of South America prefer their water to be somewhere between about 6 and 7.5pH.
Oscars do have a reputation for being aggressive, but even a small Malawi cichlid could dominate an Oscar.
Can An Oscar Live With Fancy Goldfish?
This unfortunately is another combination that isn’t going to work. You might instantly think this won’t work due to the fact that fancy goldfish live in cold water, but in fact, fancy goldfish are quite happy, they even prefer warm water.
I keep my fancy goldfish in water which is in the low 70s.
The problem with keeping Oscars and fancy goldfish together is that Oscars will completely dominate the food. They will eat everything in sight before the slower fancy goldfish have a chance. Fancy goldfish don’t have a mean bone in their bodies. The Oscars on this occasion will probably turn out to be the bullies.
Can An Oscar Live With An Arowana?
Oscars and Arowana are a classic combination, providing the tank is large enough. Arowana are long, slender fish that like to snake up and down the surface of the tank. They need a 6’ to 8’ tank minimum.
With this combination you will find the oscars live in the middle and lower regions of the tank whilst the arowana stays at the surface.
Make sure you have a VERY tight-fitting lid. At some point, your Arowana WILL jump. Without that lid, you’ll come home one day to find a dried-up Arowana on your floor.
Can An Oscar Live With Turtles?
Oscars can live with turtles, providing the tank is big enough and the filtration is powerful enough. Oscars are messy feeders and so are turtles. If your filtration isn’t up to the job and you don’t keep up with your water changes your tank will become a smelly soup before long.
Can it be done? Yes, if you are happy to put the workload in.
Can An Oscar Live With Tetras?
Although tetras, like cardinal tetras and neon tetras, live in similar waterways to Oscars, they likely won’t live long together in an aquarium. The oscar will soon grow large enough to eat the tetras.
Some of the larger bodied tetras like the CongoTetras may last a little longer, but ultimately the constant being chased by the oscar trying to eat them will prove fatal to the Congo tetras.
The rivers and waterways of South America are often hundreds of miles long and in places several miles wide. Tetras and Oscars live in close proximity, but far enough apart that the Oscar doesn’t eat them all. In the confines of an aquarium, an oscar would probably work his way through 20 or 30 neon tetras in a couple of days.
Can An Oscar Live With A Common Plecostomus?
This is another classic fish-keeping combination. It does work well. The Plecostomus tends to keep himself to himself and his ‘armored’ body is strong enough that the oscar can’t really hurt him.
Do bear in mind that the common Plecostomus grows to a very large fish. Most people don’t realize the common Plecostomus can reach 2’ in length. Also, the Plecostomus is not a ‘cleaner fish’.
He will need to be fed a dedicated diet which will probably include sinking wafers, frozen cocktail shrimp, and Repashy gel foods.
Can An Oscar Live With Koi?
Koi grow to anywhere between 2’ and 4’. They are really more suited to a pond than a tank. Koi also really want their water to be much colder than the oscar does. Koi want the water temperature to be anywhere between 55-75 degrees Fahrenheit whereas Oscars want the water to be 77-81 degrees Fahrenheit.
Koi need to be kept in ponds of 1000 gallons upwards.
Can An Oscar Live With Angelfish?
This is a definite NO. Angelfish are far too delicate to live with Oscars. Living with the more aggressive oscar will stress your angelfish to the point of death. I suspect the Oscars will ‘peck’ at the Angelfish’s long, trailing fins, which will ultimately lead to bacterial infections attacking the angelfish.
Can An Oscar Live With Clown Loaches?
This is another combination that can work really well, with one caveat, you need to find clown loaches big enough. Clown loaches grow very slowly. Oscars on the other hand grow extremely quickly. Put the two species in a tank together when both are juvenile and you’ll find after 12 months the oscar is a fully grown brute and the clown loaches have barely grown.
To make this combination work, source large clown loaches (which won’t be cheap) and add juvenile Oscars to the tank. Remember to make sure the clown loaches receive their fair share of the food. The Oscars will dominate the food if you let them.
Can An Oscar Live With Other Oscars?
Yes, this works really well, providing the tank is large enough. I try not to recommend having just two Oscars as you could have one bullying the other. If you have three or more, one fish can’t dominate the other two at the same time. The aggression is dispersed. Three Oscars however do need a fair volume of water. A 150-gallon aquarium upwards will be needed for a trio of Oscars. A 240-gallon is better still. I currently keep a trio in a 180-gallon (600 liters) aquarium and it works well, but the tank does require a LOT of water changes.
Picking the right combination of fish to live with your oscar can make a fascinating tank. Pick the wrong combination and it can be a bloodbath. Oscars are strong fish that will dominate smaller species if given the chance.
Other South American cichlids generally make the best tank mates, although most Oscars will be quite happy living alone.