Well....yes, you can. But I wouldn't expect to find your other fish in the morning. Your oscar will likely eat them.
No, cichlids require lots of space, and they are very aggressive towards other tank mates. If you want cichlids, get a large tank and only put other cichlids in it.
When choosing tank mates for cichlids, it's important to consider fish that can handle their aggressive behavior. Some compatible tank mates for cichlids include certain species of catfish (such as plecos), some species of barbs and tetras, and certain types of bottom-dwelling fish like loaches. It's crucial to research each potential tank mate's compatibility and care requirements before adding them to a cichlid tank.
6.5 to 8.3___________________ Oscars can be kept as said above in a wide range of PH, however they do best in a neutral PH as do most other South American Cichlids which Oscars are. (Neutral PH is 7.0)
If you wish to keep other fish with Oscars you will need a very large tank. The smallest tank to successfully keep 2 Oscars in is 6 foot x 2 ft x 2 ft. Other large Cichlids from the Amazon area can be kept with them. The basic rules of fishkeeping always apply. They are :- 1 inch (2.5 cm) of fish needs at least 1 gallon (3.5 ltrs) of water. :- Every tank needs a permanently running cycled filter. Every tank needs at least 50% of its water replaced every week.
The Jack Dempsey Cichlid is a a very aggressive fish and there really is no real "recommended" tank mate. Usually you are best of with Oscars and introducing them at a similar size. It is also beneficial to use a clear tank divider for introductions. Other than that i have personally had luck with other species of Amazonian and Central American Cichlids like Pike and Serverums. No matter what you are taking a risk but make sure you have a VERY large tank otherwise there will be lots of territory issues.
Sadly, no. Oscars need at least 55 gallons, but some say that an oscar needs a 75 gallon minimum. Oscars grow up to 12 inches in length, so you can understand how the measurements of your tank would be too small. Also, a goldfish needs a 55 gallon minimum. The cichlids will be aggressive, and unless your fish are about the same size as your oscar, you are going to be having a lot of fights. Also, the oscars and gold fish produce tons of waste and may kill the other fish with the extra ammonia in the water.
Oscars are large and can be aggressive, their tank should provide at least 30 gallons of space per oscar, plus any space needed for any other fish. A minimum tank size of 40 gallons is recommended if you are keeping an Oscar. 10 gallon tanks are not for keeping large cichlids in. They are for keeping a few small tetras or other small fish. When it comes to Oscars and other similar fish, the minimum sized tank I would suggest is a 72" x 18" x 18" coupled up with a large power filter.
* Oscars * Cichlids (a green terror cichlid would go great with one) * Parrot fish (that is just as equally large as the Pacu) * Red Tinfoil Barb Fish * Plecos (but has to be plecostumus, the large ones) * Red Hook Silver Dollar Fish There are numerous other aggressive, semi-aggressive freshwater fish that Pacus can be good tank mates with. Ask your local pet shops or aquarium. Make sure the Oscars aren't really aggressive.
I do
Other large, aggressive cichlids and fish such as Pacus and Jack Dempseys. Size and temperaments should be kept closely the same. Odd number of fish generally do better to help displace aggression. Tank should also be large enough to house these fish properly with enough territories. When adding new fish to an aggressive tank, feed tank fish first before releasing new fish. Also, turning aquarium lights off for the release also helps. The first few seconds of the fish entering the tank and swimming downward that are the most crucial.
There are not many fish that won't. Maybe algae eaters and large cichlids like fully grown Oscars would not be interested. But just about all Tetras, Danios, Rasboras, Barbs, Anabantids, Dwarf Cichlids, Killi fish, Livebearers etc etc will love a feed of Brine shrimp.
Convict cichlids can be semi-aggressive and territorial, especially when breeding. They may harass or even kill other fish in the tank, particularly if the tank is too small or if there are not enough hiding spots. It's best to keep them with fish of similar size and aggression levels.