June 13

Sarah Robertson

Red Oscar Fish: Hardy and Predacious Carnivore

Oscars are a type of cichlid fish, and they are native to the Amazon Basin in South America. One of the most popular Oscar is the Red Oscar fish which has distinctive reddish coloration on its body. They are very attractive fish and are popular in the aquarium trade.

The Red Oscar is a color variant of Astronotus ocellatus. They are also known as the Marble Cichlid or the Velvet Cichlid, and it's a stunning accent to any aquarium. The Red Oscar has a dark gray dorsal fin with an eyespot and orange-red coloring.

They'll mate, form a nuclear family, and are typically calm in disposition. The difference between males and females is difficult to determine, but the female has clear genital papilla during spawning.

A large aquarium of at least 70 gallons with a deep sand bottom and a few big rocks is required for the Red Oscar. They'll dig up plants, so cover the root surfaces with stones any that are in the tank. This issue may be alleviated by utilizing floating plants.

Oscars that are less than 1 inch long will congregate together for protection, which is typical juvenile fish behavior. When a full-grown Oscars is hungry, it is not as territorial as other cichlids. It will, however, eat whatever it can cram into its mouth.

The largest tank available should be utilized for breeding, if possible. A 100-gallon tank will be ideal for breeding. The Red Oscar can spawn in both soft and hard water as long as the water is clean and clear, with a temperature between 79-86°F. On clean, smooth rocks, the female will lay around 1,000-2,000 eggs.

At first, the eggs are opaque and turn transparent after 24 hours. The eggs will be guarded and cared for, and the fry will be kept in pits or at least covered. The fry should be fed Cyclops when they are free-swimming. The fry may occasionally cling to their parents.

The Red Oscar is a carnivore that is both predacious and hearty. Oscars will consume a range of meaty meals, including tiny fish and earthworms, Cichlid pellets, larger flake food, ocean plankton, bloodworms, and tubifex worms.

Red Oscar Fish Care 

Like all other Oscars, Red Oscars require clean, fresh water in their tanks and proper food. They require a good quality filtration system. They also have additional requirements because of their large size and strength.

Choosing the Aquarium for Proper Oscar Care 

Oscars are among the largest freshwater fish that average hobbyists have a chance of keeping successfully, and it's not uncommon for them to grow up to 18 inches long. Because they can become very big, you will need an aquarium that accommodates them comfortably. Here are few things to consider while choosing an aquarium for your Oscar:

  • Keep a single fish in a 75-gallon tank, or two Oscars in an aquarium with a volume of at least 100 gallons. Oscar fish require a 200-gallon tank or larger if you have more than two. If this sounds like too much, bear in mind that these enormous fish need adequate room to swim and move about.
  • Place your aquarium on a solid foundation or table and in an area where you can access your fish and observe them.

  • Make sure the tank and stand are perfectly level. An uneven tank puts extra strain on the side panel seals, which may lead to leaks.

Add a Good Quality Filtration System 

Filtration is essential for all home aquariums, but it's especially critical for Oscar systems. This is due to the large amount of waste they produce, also known as their "bioload."

For your Oscar fish habitat, you'll need a three-stage filtration system. There are three components to this intricate scheme.

Mechanical filtration: In this filtration system Waste is physically strained and removed through the aquarium filter by equipment components that are located at the filtration water intake or early in the filtering loop. Some aquarium filtration systems only utilize mechanical filtering, but it is insufficient for many fish.

Chemical filtration: The next step is to introduce chemically reactive media into the filtration system. These chemicals are used by aquarists to remove dangerous chemicals from aquarium water. Activated charcoal is a well-known chemical filtration medium, and many systems utilize it for this purpose. Chemical filtering media, on the other hand, may become clogged with unwanted chemicals after a certain period of time, and must be replaced frequently to be successful.

Biological filtration: Biological filtration is the most difficult yet important approach utilized in aquarium filtering systems. Ammonia is generated by fish during respiration and excretion. If steps aren't taken to break down ammonia into less dangerous chemicals, such as nitrates, it can quickly accumulate and harm fish. Fortunately, biological filtration transforms toxic ammonia and nitrite into less-harmful nitrate. It's all about the good bacteria in your filter, which are utilized to break down nitrogen and nitrite. If levels get too high, the resulting nitrates are still harmful, so regular water changes are required to remove this final waste product from the system. Bacteria is also good for your fish in this scenario.

Red Oscar Fish Size

Red Oscar Fish Size 

The Oscars may grow up to 12 inches (1ft) in length. It takes them approximately one year to reach their full size, which is roughly an inch every month.

Red Oscar Fish Lifespan 

Oscars can survive for up to 20 years! Oscar fish care is what ensures their longevity. Keep in mind that fish do not live happily together. You must ensure that the tank environment is correct and that its tank mates are compatible.

Their life expectancy is also determined by their diet and feeding patterns. Overfeeding can cause health problems that shorten their lifespan.

Red Oscar Fish Appearance 

The Red Oscar fish is an exceptional example of extraordinary beauty. They're made up of two distinct hues, red and black. The intensity of redness may vary from fish to fish, and the black spots may be more or less pronounced. The red Oscar’s two distinct hues are readily apparent and merge flawlessly into each other.

Each Red Oscar fish appears different from one another in terms of the intensity of color and the pattern of black spots. On the basis of that Red Oscars are often graded and priced. Following are some of the different color morphs of Red Oscars:

Red Tiger Oscar Fish: The Red Tiger Oscar is a color morph of the Red Oscar. The only difference between these two species is their coloration. The Red Tiger Oscar has a black and white striped pattern that runs vertically along its red body.

Black and Red Oscar Fish: The Black and Red Oscar is another color morph of the Red Oscar. As the name suggests, this species has a black body with red spots.

Platinum Red Oscar Fish: The Platinum Red Oscar is the result of a rare genetic mutation. This color morph has a pale white body with red spots.

Red Oscar Fish Behavior 

Red Oscar fish are known for their personality, which makes them a popular choice among fish enthusiasts. Some Oscars may even be hand-fed. Keep in mind that these sociable fish will become bored and depressed if they don't get enough attention, so pay attention to them.

Although intelligent Oscars can be loving with their owners, they are not sociable fish. They have a well-deserved reputation for being aggressive toward other fish and aquatic life. As a result, many hobbyists choose to maintain tanks solely for their Oscars.

Red Oscar Fish Diet 

When it comes to what to feed your Oscar fish, there are several options. They are not fussy eaters and will accept most food, including live, frozen, or pellets.

It's important to choose a complete commercial diet specially developed for Oscars, which are more often sold in the form of pellets. Although these balanced diets provide your Oscar with all of the nutrients they require, some pet parents choose to give their Oscars additional food or rewards.

It's crucial to know that Oscars and other cichlids are omnivores. It's also possible to offer your Oscar fruits or vegetables, such as green peas or tiny bites of apple.

Most sellers also sell their cichlids frozen, dried, or live bloodworms as well as mealworms. Consider adding these foods to your commercial diet as a great complement, but be sure that you're getting clean live foods free of parasites and illnesses.

In the wild, Oscars consume live prey, but many modern hobbyists avoid providing live feeder fish in aquariums. Parasites or illnesses may be carried via these feeders and cause harm to your Oscars, as well as the whole tank environment. If you decide to sell your Oscars live feeder fish, make sure they are of excellent quality and health.

Remember that what goes in must eventually come out, and Oscars are known for producing a lot of trash. To prevent the accumulation of uneaten food and waste, don't overfeed your Oscar. Offer them only as much food as they can finish in 5 minutes twice a day, and Keep any uneaten food away from the tank to prevent rotting and to maintain water quality.

This implies you must keep an eye on your Oscars while they eat. it's a great way to spend time with your fish and prevent problems from developing before they become serious.

Red Oscar Fish Tank Mates 

It's crucial to think about other species you already have or may want to add to your tank before purchasing an Oscar. Oscar fish are not safe in most community aquariums due to their aggressive natures. It's best to set up a tank that's specifically for your Oscar fish, or choose tank mates that can stand up to their aggression.

Other cichlids, particularly the green terror and Jack Dempsey, are on the list of possible tank mates for Oscars. However, it's not uncommon for Oscars to develop a hostile temperament and fight with these fish species, sometimes even to the death.

If you want to put Oscars in a tank with other fish, make sure there's enough room and hiding places for them. You must also keep an eye on how these fish interact with one another and separate them if necessary.

Some examples of suitable tankmates for Red Oscars include:

  • Arowana

  • Green Terror
  • Bichir
  • Sailfin Pleco
  • Jack Dempsey
  • Convict cichlid

Other large cichlids, on the other hand, are typically able to defend themselves or keep out of the way when necessary, in most cases.

To summarize, any fish that can be eaten is not suitable for living in an aquarium with Oscars. The same may be said for Shrimp, snails, and other tiny invertebrates.

red oscar fish

Red Oscar Fish Tank Setup 

Now that you know a little more about these fascinating fish, it's time to start setting up your tank. If you're looking for ideas on how to get started, here are some tips on setting up the perfect Oscar fish tank.

Ideal Water Conditions for Oscars 

Red Oscar fish are sensitive to pollutants, so ammonia and nitrite levels must be closely monitored. If nitrites levels exceed 20 ppm, Oscars will suffer. 10 ppm is the maximum amount of nitrite that should be present in a freshwater aquarium for Red Oscar fish. However, keeping nitrite levels as close to zero as possible is preferable. Nitrite test kits are available to monitor the levels in your tank.

Your goal when creating an aquarium should be to keep the tank's water at a level that would be normal for your fish in the wild. The optimum water pH for Red Oscars is between 6 and 8. Use a cichlid buffer or a water conditioner specifically for cichlids, and test the pH of the aquarium water with an aquarium water pH test kit.

Temperature for Oscar Fish 

Keep in mind that Oscar fish are native to hot, tropical regions. Maintain temperatures between 75- and 80-degrees Fahrenheit, which is best achieved at around 77 degrees. You may do this by keeping the aquarium water at a particular temperature using an aquarium heater.

As Oscars have been recorded to shatter glass heaters, avoid using them. Shatterproof aquarium heaters are available that may be used in Oscar aquariums.

Lights and Tank Hoods Are a Must for an Oscar Tank 

The Oscars can leap and have been observed leaping to their deaths out of an open-top aquarium. It's crucial that you secure your aquarium to avoid this situation.

  • Purchase a light fixture and hood that match properly and securely over the top of the aquarium.
  • To protect your fish and keep them healthy, you must use a glass top or plastic hood to enclose the aquarium.
  • Make sure the tank hood flaps have a clasp on them, or use bricks to keep them closed. They might break them if they hit the aquarium hood while leaping.

Gravel, Plants, and Accessories 

The habit of rooting among the decorations in their tanks is one of the most fascinating features about caring for Oscar fish. They can easily remove plants or even shift gravel across the aquarium floor. It's possible that they'll dig trenches in the substrate, move your carefully positioned plants, and otherwise alter the tank.

Consider adding artificial plants to the aquarium if this behavior causes you a lot of money, especially because they pull up live plants. Your Oscar won't mind. You may also secure decorations to the aquarium bottom before adding substrate or glue them directly to the tank.

Red Oscar Fish Breeding 

Unfortunately, Oscars are one of the most difficult fish to breed in captivity. When it comes to selecting a partner, they are extremely picky and like to select their own partners rather than having you choose for them!

The best method is to purchase a mated pair. Alternatively, you may buy a handful of juvenile Oscars and let them pair off as they grow up. Because Oscars aren't sexually mature until they're one or two years old, if you choose to go that route, you may have to wait a long time before any offspring are generated.

Spawning behavior 

Red Oscars reproduce in the wild during the rainy season. To simulate this in your home aquarium, you'll need to reduce the temperature by a few degrees. To simulate a downpour, carry out water changes every other day and sprinkle the surface with water several times each day.

During spawning, the male fish expands his gills and shows them to his partner. The pair cleans a flat stone surface clean so that the eggs may be placed. Large females may lay as many as 3,000 opaque white eggs during a single spawning.

Both the parents guard the eggs until they hatch, which is generally within two to three days. During this time, the male chases away other fish from the nest to protect the egg whereas the females fan the eggs to keep them clear of a crust of substrate during that time.

After the fry hatch, transfer them to a separate tank with a sponge filter. To enhance growth, feed the youngsters four times a day for the first two weeks and then twice daily for the following five months. To prevent stunted development, move the juvenile oscars to a larger tank as they grow.

Red Oscar Fish Fry 

Red Oscar fry are black when they hatch and develop their coloration as they grow. Juvenile Oscars have dark vertical stripes on their bodies, which eventually fade as the fish reach maturity.

Raising the fry is not an easy task. The reason being, they are highly cannibalistic in nature and have to be segregated according to their size. The bigger fry will feed on the smaller ones if they are not moved to a separate tank.

To prevent this, it is advisable that you move the fry to a different tank as soon as they hatch. The tank should have a sponge filter and the water should be changed every other day.

Red Oscar Fish Diseases

Red Oscar Fish Diseases 

Red Oscars are susceptible to a number of diseases, the most common being bacterial and fungal infections.

Here are some of the diseases that your Red Oscar might suffer from:

Hole-in-the-Head Disease (HITH) 

The exact cause of HITH disease is unknown. However, it's thought that the parasite Hexamita might be responsible. Overcrowding, mineral or vitamin deficiencies, an improper diet, and poor water quality are just a few of the causes.

HITH causes pitting and ulcers on the head and lateral line of the fish, white sores on top of the fish's head and around its eyes, significant holes and sores on the body that weep mucus, and a poor appetite.

If left untreated, This disease can even be deadly. If you can get your fish to eat medicated fish food, try metronidazole on it. You can soak your fish in it for 6 to 12 hours in it.

The only way to cure the disease is to treat it, but you'll need to address any poor husbandry that may have caused the problem in the first place.


Ich is a disease that affects all sorts of aquarium fish species and is also known as white spot disease.

It's caused by the Ichthyophthirius multifiliis protozoan parasite. The parasite most often enters your tank via plants, new fish, or live food. Ich is a disease that may be fatal if not detected and treated early. Signs include an absence of appetite, red patches on the fins, rapid breathing, and flicking or rubbing the body against the substrate or other aquarium decorations.

Increasing the water temperature to 82 degrees Fahrenheit for three days and treating the water with an over-the-counter white spot treatment from your local fish store can help cure ich.

Columnaris (Fin Rot) 

The most common reason for fin rot is a bacterial infection. However, stress, overcrowding, poor water quality, and low oxygen levels may all play a role. Occasionally, the condition may establish in tissue that has been injured through trauma or abrasion.

Ripped and bloody fins, partial tail or fin loss, lethargy, poor appetite, hanging at the water's surface, and slime or semi-transparent appearance of the body or fins are all signs of columnaris.

Antibiotic medication from a fish store can be used to treat this disease. It's also possible to do a 30 percent water change before treatment, and you may use aquarium salt as directed on the package.

Popeye Disease 

Keeping your fish in tanks with chronically poor water conditions will usually induce Popeye disease. The most common signs of popeye include bulging, swelling, or cloudiness in one or both eyes.

The condition damages the cornea and causes fluid to build up behind the eye, with a possible secondary bacterial infection.

Popeye's illness can be treated by correcting the water conditions and using over-the-counter antibiotic medication.

Dropsy or Bloat 

Rather than having a single cause, bloat or dropsy is a severe illness that may be induced by a variety of factors.

The most frequent reason for dropsy is constipation caused by overfeeding. Swollen abdomen, bloated appearance, erratic swimming, and lack of feces trailing behind the fish are all symptoms of constipation. You may often cure constipation by skipping meals for 48 hours and then feeding live or frozen meaty foods.

A fish with dropsy will have a distended belly and pinecone-like scales. The fish will most likely cease feeding and exhibit signs indicating that it is having difficulties swimming. Dropsy is a far more serious condition that may kill a fish if not treated.

Red Oscar Fish Availability 

Red Oscars are usually available in most fish stores and online. Price varies depending on the size of the fish, typically starting at just a few dollars per fish for an oscar whose size is around three or four inches long.

Full-grown Red Oscars, on the other hand, can cost upwards of $50 or more.

What Size Tank Does a Red Oscar Need


What Size Tank Does a Red Oscar Need? 

A minimum of 50 gallons is recommended for a single red Oscar, with 75 gallons being even better. If you plan on keeping more than one Oscar fish, you'll need an additional 50 gallons for each extra fish.

How Big Does a Red Oscar Get? 

The average size for a full-grown red Oscar is about 10 to 15 inches long, with some individuals reaching up to 20 inches in length.

How Fast Do Red Oscars Grow? 

Red Oscar fish grow quickly, reaching their full size in just a few years. Oscars that are well-fed can grow up to an inch or more per month.

What Do Red Oscars Eat? 

In the wild, red oscars are predators that feed on smaller fish, crustaceans, insects, and other aquatic creatures. In captivity, they will accept a variety of foods, including pellets, flakes, live foods, and frozen foods.

Do Red Oscars Have Teeth? 

Yes, The Red Oscars have teeth in their jaws as well as a pair of pharyngeal teeth. Teeth in the jaws are tiny and are used to grab prey, whereas those in the throat are larger and are utilized for grasping and processing meat. With the help of these teeth, they mash the food before swallowing.

Do Red Oscars Eat Plants? 

Yes, Red Oscars are known to nibble on soft, live plants. While they don't typically uproot or damage plants, they may consume plant matter that is small enough to fit into their mouth. If you keep red Oscars with live plants, it's best to choose robust species that can withstand a little nibbling.


The red oscar fish is a popular freshwater aquarium fish that is known for its vibrant coloration and playful personality. These hardy fish are relatively easy to care for, but they do require a large tank and regular maintenance to stay healthy. If you're looking for a beautiful and unique addition to your freshwater aquarium, the red oscar fish is a great choice!

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

{"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

Subscribe to our newsletter