Can Oscar Fish And Discus Fish Live Together?

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Both Oscar fish and Discus fish are fascinating and beautiful creatures. But can you actually keep them together in the same tank?

Since I get this question a lot, I decided to dedicate an entire article to the topic, answering it once and for all.

Here, I’ll discuss the behavior characteristics of each species, their water and tank requirements, and explain whether you can keep both together.

So, without further ado, let’s get started.

Can I Keep Oscar Fish And Discus Fish Together In The Same Tank?

No, Oscar fish and Discus fish are not typically recommended to be kept together in the same tank.

Their differing requirements and behaviors can lead to challenges in maintaining a harmonious environment.

Here are some reasons to consider:

  • Temperature Preferences: Oscars flourish between 74-81°F, whereas Discus favor 82-86°F, posing a challenge to satisfy both in a single aquarium.
  • Territorial Tendencies: Oscars tend to be assertive, potentially stressing or injuring the gentler Discus, particularly during food times or boundary disagreements.
  • Size and Growth Patterns: Oscars can achieve 12-14 inches and grow swiftly, possibly overshadowing and intimidating the smaller Discus, who max out at 8-10 inches.
  • Feeding Requirements: Oscars enjoy a diverse menu, but Discus necessitate particular high-grade feeds, resulting in potential rivalry and wellness concerns.
  • Decor and Environment Choices: Oscars might adjust tank decorations, whereas Discus seek consistency, leading to dilemmas in tank arrangement.

Also Read: 19 Great Oscar Fish Tank Mates

Oscar Fish vs. Discus Fish: Behavior

The first factor worth considering is the Oscars’ and Discus’s natural behavior. Here is what you should know:

Oscar Fish: Natural Behavior

Oscars stand out because of their unique temperaments. As they grow older, some can get a bit feisty.

Their behavior mirrors what you’d expect if they were out in the wild, staking claim to their territories. Here’s the scoop on Oscar fish:

  • Aggressiveness: Oscars can get territorial, especially when it’s breeding time or they feel their space is invaded, leading to some tank drama.
  • Mobility and Exploration: Oscars are quite the adventurers. They love swimming around, checking out every nook and cranny, and they aren’t shy about rearranging tank decorations.
  • Predatory Instinct: In the wild, Oscars are the hunters, snacking on smaller fish, insects, and crustaceans. They carry this hunting spirit even when in a tank.
  • Social Rank: If you have a few Oscars together, they’ll figure out who’s boss, which can sometimes lead to a bit of push and shove.
  • Emotional Displays: Oscars wear their hearts on their scales. They change colors depending on their mood, health, or if something in the tank isn’t quite right. Darker colors usually mean they’re not too happy.

Discus Fish: Natural Behavior

On the flip side, Discus fish are the peacekeepers. They’re often dubbed the “gentle giants” of the aquarium scene because of how chill they are.

Here’s what you should know about Discus:

  • Gentle Nature: Discus are the cool, calm types. They get along well with other laid-back tank buddies.
  • Group Behavior: Unlike the more lone-wolf Oscar, Discus enjoy company. They often swim in groups, finding safety in numbers, just as they would in the wild.
  • Quiet Interaction: Discus have their way of communicating, mainly through subtle movements and color changes, especially during special moments like breeding or marking territory.
  • Dietary Preferences: Discus are a bit picky with their food. They lean toward the high-end stuff and aren’t as much into hunting as Oscars are.
  • Environmental Sensitivity: Discus appreciate stability. Changes in water quality or their surroundings can throw them off, so they need a consistent and clean environment to thrive.

Ideal Parameters For Oscar Fish And Discus Fish

Both Oscar fish and Discus fish have specific water conditions they thrive in. Here’s a quick comparison of their ideal parameters.

ParameterOscar FishDiscus Fish
Temperature74-81°F (23-27°C)82-86°F (28-30°C)
pH Level6.0 – 8.06.0 – 7.5
Water Hardness5-20 dGH3-10 dGH

Oscar Fish: Ideal Parameters

Oscar fish, originating from the Amazon basin, thrive best under certain water conditions, revealing their optimal health and vibrant colors.

Creating the right habitat is key to their prolonged well-being and contentment. Here are the optimal conditions for Oscar fish:

  • Temperature: Oscars flourish in temperatures between 74-81°F (23-27°C), promoting their activity and showcasing their innate behaviors.
  • pH Level: Oscars gravitate towards water that’s mildly acidic to neutral, favoring a pH value of 6.0 to 8.0, mirroring their native Amazon environment.
  • Water Hardness: For Oscars, water that’s soft to moderately hard, in the range of 5 to 20 dGH, mirrors the mineral composition they’re used to.

Discus Fish: Ideal Parameters

Discus fish, also from the Amazon, have distinct needs compared to Oscars.

They’re recognized for their water sensitivity and have specific needs for peak health. Here’s what you should know::

  • Temperature: Discus fish thrive in warmer conditions, favoring temperatures of 82-86°F (28-30°C) to boost their metabolic functions and overall health.
  • pH Level: For Discus, a mildly acidic pH value from 6.0 to 7.5 replicates the water characteristics of their original habitat.
  • Water Hardness: Soft water is essential for Discus, with a suggested hardness of 3 to 10 dGH, ensuring they maintain a stress-free and healthy state.

Also Read: Can Oscar Fish And Arowana Fish Live Together?

Oscar Fish vs. Discus Fish: Tank Setup

Tank setup plays a crucial role in ensuring the health and well-being of both Oscar fish and Discus fish. The following table illustrates the key setup differences.

Setup ComponentOscar FishDiscus Fish
Ammonia/Nitrite/NitrateAmmonia/Nitrite: 0 ppm, Nitrate: <40 ppmAmmonia/Nitrite: 0 ppm, Nitrate: ideally <20 ppm
Tank SizeMinimum 75 gallonsMinimum 50 gallons
FoliageSturdy/Artificial plantsDensely planted (e.g., Amazon Swords)
DecorationsLarge, stable decorationsSmooth with no sharp edges
FilterPowerful, 3-4x tank’s volume per hourGentle yet efficient
SubstrateLarger-grained substrate or sandFine sand or smooth gravel
PumpGood circulation pumpGentle circulation pump
LightingModerateSoft, diffused

Oscar Fish: Tank Setup

The tank setup for Oscar fish should consider their active nature and propensity for growth. 

Ensuring that their environment resembles their natural habitat not only satisfies their instinctual needs but also promotes healthier, happier fish.

For the ideal Oscar fish setup, one should consider:

  • Ammonia, Nitrite, Nitrate: Regular water testing is vital for Oscars, with ammonia and nitrite levels at 0 ppm, and nitrate kept below 40 ppm for optimal health.
  • Tank Size: Given the size Oscars can reach (up to 14 inches), a minimum tank size of 75 gallons for a single Oscar is recommended.
  • Foliage: Oscars aren’t very plant-friendly; sturdy and anchored plants or artificial plants are preferred to prevent uprooting.
  • Decorations: Oscars are known to rearrange their space, so large, stable decorations that can’t be easily moved are ideal.
  • Filter: A powerful filtration system, handling at least 3-4 times the tank’s volume per hour, ensures clean water for Oscar fish.
  • Heater: A reliable heater maintaining a temperature of 74-81°F (23-27°C) is crucial for the Oscar’s well-being.
  • Substrate: Oscars aren’t picky, but larger-grained substrate or sand can be used, making it harder for them to dig up.
  • Pump: A good circulation pump ensures even water temperature and prevents stagnant areas in the tank.
  • Lighting: Moderate lighting is fine for Oscar fish; they don’t have specific lighting needs.

Discus Fish: Tank Setup

Discus fish, often regarded as the “kings and queens” of the freshwater aquarium world, have specific requirements due to their sensitivity.

Their setup needs precision to replicate the soft, acidic waters of the Amazon. The following are vital components for a Discus tank:

  • Ammonia, Nitrite, Nitrate: For Discus, it’s essential to maintain ammonia and nitrite at 0 ppm and nitrates as low as possible, ideally below 20 ppm.
  • Tank Size: Discus fish require spacious environments; a 50-gallon tank is the minimum for a small group, with more space as they grow.
  • Foliage: Discus appreciate densely planted tanks; plants like Amazon Swords or Vallisneria provide comfort and mimic their natural habitat.
  • Decorations: Gentle, smooth decorations with no sharp edges are ideal for Discus to prevent injuries.
  • Filter: A gentle but efficient filtration system is needed, ensuring clean water without creating strong currents.
  • Heater: Discus thrive in warm waters, so a heater maintaining 82-86°F (28-30°C) is essential.
  • Substrate: Fine sand or smooth gravel is suitable for Discus, reflecting the soft riverbeds of the Amazon.
  • Pump: A pump ensuring gentle water circulation is vital to prevent stress and ensure even water temperatures.
  • Lighting: Soft, diffused lighting is preferred for Discus, creating a calm environment and showcasing their vibrant colors.

Also Read: Can Oscar Fish And Blood Parrot Cichlids Live Together?

The Dietary Requirements Of Oscar Fish And Discus Fish

Both Oscar fish and Discus fish have specific dietary needs that cater to their health and growth. Below is a brief comparison.

Dietary ComponentOscar FishDiscus Fish
Food TypesHigh-quality pellets, live foods, vegetablesHigh-quality pellets/flakes, beef heart, frozen foods
Quantity2-3% of body weight dailySmall pinch, eaten in 3-5 mins
Feeding ScheduleOnce or twice a day2-3 times a day

Oscar Fish: Ideal Dietary Requirements

Oscar fish, being omnivorous, exhibit a strong predatory instinct and require a varied diet to ensure they receive all essential nutrients.

Balancing commercial food with live or frozen varieties can offer a rounded diet. The dietary needs of Oscar fish include:

  • Food Types: Oscars thrive on a mix of high-quality pellets, live foods (like crickets or feeder fish), and occasional vegetable matter for optimal health.
  • Quantity: Adult Oscars usually consume 2-3% of their body weight every day. This often equates to several pellets or its equivalent.
  • Feeding Schedule: Oscars should be fed once or twice daily. Ensure they finish their meal in a short span to avoid overfeeding.

Discus Fish: Ideal Dietary Requirements

Compared to Oscars, Discus fish necessitate a more refined diet. They’re carnivores and require particular foods to sustain their bright hues and health.

Key components of a Discus diet include:

  • Food Types: Discus lean towards premium pellets or flakes, mixes of beef heart, and frozen treats like bloodworms and brine shrimp.
  • Quantity: Discus should be given a minor amount of food, making sure it’s fully consumed in 3-5 minutes, and adjusted based on the number and size of the fish.
  • Feeding Schedule: Offering food to Discus 2-3 times daily in smaller portions can support regular growth and preserve their vibrant shades.

Guidelines for Housing Oscars with Discus:

It’s typically discouraged to house Oscars with Discus due to their contrasting needs and behaviors.

However, with meticulous arrangement and observation, coexistence might be feasible. Here’s what you should do:

  • Tank Capacity: Choose an exceedingly spacious tank, no less than 150 gallons, ensuring both Oscars and Discus can delineate their territories.
  • Designated Areas: Structure separate sections in the tank with foliage and ornaments. This lets both fish species have individual spaces, minimizing potential hostility from Oscars.
  • Temperature Checks: Target a middle-ground temperature, roughly 80°F (27°C). It’s a potential compromise for both Oscars and Discus, even if not perfect for either.
  • Varied Diet: Ensure both species receive their specific dietary needs; high-quality pellets for Oscars and specialized food for Discus, served in separate areas.
  • Regular Monitoring: Watch closely for signs of stress or aggression, especially from the Oscar fish, and be ready to separate them if necessary.
  • Adequate Filtration: Given the waste produced, especially by Oscar fish, invest in a powerful filter to keep water conditions optimal.
  • Frequent Water Changes: To accommodate the sensitive nature of Discus and the messiness of Oscar fish, perform regular water changes, ideally once a week.

Should I Opt for an Oscar or a Discus Fish

Deciding between an Oscar fish and a Discus fish depends on your personal preferences, aquarium setup, and level of experience in fishkeeping.

Both have unique requirements and temperaments that cater to different types of hobbyists. To help you in your decision, consider the following factors:

  • Care Level: Oscar fish are more forgiving and adaptable, making them suitable for intermediate aquarists, while Discus fish require more attention and expertise.
  • Tank Size: Oscar fish grow larger and need substantial space; a minimum of 75 gallons is recommended, whereas Discus can start in a smaller 50-gallon setup but prefer groups.
  • Behavior: Oscar fish exhibit stronger territorial behaviors and can be more aggressive, while Discus are calmer and more community-oriented.
  • Aesthetic Appeal: While Oscar fish have dynamic personalities and come in various colors, Discus fish are renowned for their stunning, vibrant colorations and disc-shaped bodies.
  • Maintenance: Oscars can be messier, necessitating frequent water changes and strong filtration, whereas Discus require stable water conditions and are sensitive to changes.


For those of you who are just skimming through, here’s a short recap:

  • Oscar and Discus fish have distinct temperature, aggression, size, diet, and habitat needs, making joint housing difficult.
  • Oscar fish exhibit aggression and territorial behavior, while Discus fish are peaceful and tend to school.
  • Tank setups must suit Oscars’ activity and Discus’ sensitivity, and water conditions must align with their native habitats.
  • Oscars demand varied diet, including live foods, while Discus need high-quality pellets and flakes.
  • Cohabitation requires careful planning, large tanks, separate territories, and compromises in temperature and diet.