Arowana Fish In Small Tank – A Comprehensive Guide To Sustainable Care

Written ByHoward Parker

Hey there, fellow aquarist! Have you ever gazed at the majestic arowana, with its shimmering scales and regal presence, and dreamed of having one grace your home aquarium? You’re not alone! These incredible fish are truly captivating. But then, the big question pops into your head: “Don’t arowanas need absolutely massive tanks?” It’s a common concern, and a perfectly valid one. Many enthusiasts believe that keeping an arowana fish in a small tank is impossible, or even cruel. But what if I told you that, with the right knowledge, planning, and a commitment to their well-being, you absolutely can provide a fantastic home for a juvenile arowana, even if you don’t have a monstrous display tank right now?

At Aquifarm, we’re all about helping you create beautiful, thriving aquatic environments. We understand the allure of these magnificent creatures and the desire to responsibly bring one into your life. That’s why we’ve put together this comprehensive guide. We’re going to dive deep into the world of arowana fish in small tank tips, dispelling myths, sharing expert advice, and showing you how to arowana fish in small tank environments responsibly. By the end of this article, you’ll have a clear roadmap for success, ensuring your beautiful arowana thrives from its juvenile stage, with a solid plan for its future. So, let’s get started on this exciting journey!

Understanding the Myth: Can Arowana Fish Thrive in Small Tanks?

The idea that arowanas *only* belong in colossal aquariums isn’t entirely wrong, but it’s often misunderstood, especially when it comes to juveniles. Adult arowanas, particularly species like the Silver Arowana, can reach lengths of 3 feet or more! Naturally, a fish of that size requires an enormous amount of space to swim, turn, and live comfortably.

However, the journey of an arowana begins much smaller. When you purchase a juvenile arowana, it’s typically only 4-8 inches long. At this stage, a well-maintained, appropriately sized “small” tank (which we’ll define shortly!) can be a perfectly suitable, and even beneficial, environment.

The key here is responsible husbandry and a clear understanding that a “small tank” for an arowana is often a temporary, though vital, stage. This approach allows you to enjoy these incredible fish during their most active growth phase while preparing for their adult needs. It’s not about forcing a large fish into a tiny space; it’s about providing optimal conditions for a growing fish and having an upgrade plan in place.

Choosing the Right Arowana for Your Smaller Aquarium

This is perhaps the most critical step in successfully keeping an arowana fish in a small tank. Not all arowana species are created equal, and some are simply unsuitable for anything less than monumental setups, even as juveniles. Making the right choice ensures a healthier, happier fish and a more manageable experience for you.

The Ideal Candidates for Juvenile Care

When considering sustainable arowana fish in small tank keeping, you’ll primarily be looking at these species, keeping their ultimate size and growth rate in mind:

  • Silver Arowana (Osteoglossum bicirrhosum): This is the most commonly available and often the most affordable arowana. Juveniles are stunning and grow rapidly.
    • Pro Tip: A juvenile Silver Arowana (up to about 12-15 inches) can thrive in a 75-gallon to 125-gallon tank initially. However, be prepared for a rapid upgrade to 200+ gallons, and eventually 300-500+ gallons as an adult. Their growth is truly impressive!
  • Australian Jardini Arowana (Scleropages jardinii): Also known as the Gulf Saratoga or Northern Barramundi, these are stockier and typically reach 1.5 to 2 feet in length as adults. They are a bit more aggressive but can be a good choice for those wanting a slightly smaller adult arowana than the Silver.
    • Pro Tip: A 125-gallon tank can house a juvenile Jardini for a longer period than a Silver, but a 180-gallon minimum is recommended for sub-adults, with 250+ gallons ideal for an adult.

Remember, “small tank” here is relative. For an arowana, even a 75-gallon tank is considered small when discussing its entire lifespan. We’re talking about providing adequate space for a *growing* fish, not its permanent home.

Species to Avoid (Especially for Smaller Tanks)

While incredibly beautiful, some arowana species are simply not suitable for smaller aquarium environments, even temporarily, due to their immense size, specialized needs, or protected status:

  • Asian Arowana (Scleropages formosus): These are highly prized, very expensive, and often protected by CITES. They can reach similar sizes to Silver Arowanas but are often more sensitive and require extremely specific water parameters and a massive amount of space. Their care is best left to highly experienced aquarists with very large, dedicated setups.
  • Black Arowana (Osteoglossum ferreirai): While stunning, they grow very large and are similar in care to Silver Arowanas, requiring equally large tanks for adults.

The decision to bring an arowana home is a long-term commitment. Always research the adult size and temperament of the specific species before purchase. This is a fundamental part of providing a truly sustainable arowana fish in small tank experience.

Setting Up the Perfect Small Arowana Tank Environment

Once you’ve chosen your arowana species, the next step is creating an environment that will allow it to thrive. This is where the real work of arowana fish in small tank best practices comes into play.

Tank Size & Dimensions: More Than Just Gallons

For a juvenile arowana (up to 12-15 inches), a tank of at least 75 gallons is a good starting point. However, dimensions are more important than mere volume. Arowanas are long, active swimmers, so length and width are crucial.

  • Minimum for Juveniles: Aim for a tank that is at least 4 feet long (48 inches), 18 inches wide, and 20 inches high (e.g., a standard 75-gallon or 90-gallon tank). A 125-gallon (6 feet long) would be even better and buy you more time.
  • Why Length Matters: Arowanas need space to turn around without constantly bumping into glass. A longer tank reduces stress and prevents fin damage.

Remember, this is a temporary home. You absolutely must have a plan for a much larger tank (200+ gallons) within 6-12 months, depending on your fish’s growth rate.

Filtration: The Heart of Your Aquarium

Arowanas are messy eaters and produce a significant bio-load, even as juveniles. Over-filtration is not just recommended; it’s essential.

  • Canister Filters: Multiple large canister filters are excellent. Look for models with high GPH (gallons per hour) ratings and ample space for mechanical, biological, and chemical media.
  • Sump Systems: For larger setups, a sump offers unparalleled filtration capacity and water volume.
  • Sponge Filters: Can be used as supplemental biological filtration, especially during cycling or for extra aeration.

Regular maintenance of your filters is critical. Clean mechanical media weekly and rinse biological media in old tank water every few weeks to prevent beneficial bacteria loss.

Water Parameters: Arowana’s Comfort Zone

Stable water conditions are paramount for the health of your arowana fish in small tank setups. Sudden fluctuations can cause immense stress and lead to illness.

  • Temperature: Keep it stable between 75-82°F (24-28°C). Use a reliable heater (or two, for redundancy).
  • pH: Arowanas prefer slightly acidic to neutral water, typically pH 6.0-7.5. Consistency is key; avoid chasing a specific number.
  • Ammonia, Nitrite, Nitrate: Ammonia and nitrite should always be 0 ppm. Nitrates should be kept below 20 ppm through regular water changes. Invest in good liquid test kits.
  • Water Changes: Weekly 25-30% water changes are non-negotiable to dilute nitrates and replenish essential minerals. For juveniles in smaller tanks, you might even need more frequent changes.

Substrate, Decor & Lighting

  • Substrate: A bare bottom tank is easiest for cleaning and monitoring waste. If you use substrate, opt for fine, smooth sand to prevent injuries. Avoid sharp gravel.
  • Decor: Keep it simple. Arowanas need swimming space. A few large, smooth river rocks or a piece of smooth driftwood can provide enrichment without clutter. Ensure all decor is stable and won’t fall.
  • Lighting: Moderate lighting is fine. Arowanas are not particularly demanding regarding light intensity. Avoid harsh, direct light which can stress them.
  • Lid: This is perhaps the most important piece of equipment. Arowanas are champion jumpers! A heavy, secure, tightly fitting lid with no gaps is an absolute must. Many an arowana has ended up on the floor because of an unsecured lid.

Nutrition and Feeding for a Healthy Arowana Fish in a Small Tank

Feeding your arowana correctly is vital for its growth, vibrant coloration, and overall health. A varied and nutritious diet is key to how to arowana fish in small tank setups thrive.

Diverse Diet is Key

Arowanas are primarily carnivorous. While juveniles might accept flakes or small pellets, they quickly outgrow them. Offer a diverse diet to ensure they receive all necessary nutrients:

  • High-Quality Pellets: Specially formulated arowana pellets can be a staple, providing balanced nutrition. Look for brands with high protein content.
  • Frozen Foods: Krill, bloodworms, Mysis shrimp, silversides, and chopped fish fillets (tilapia, salmon) are excellent choices. Thaw thoroughly before feeding.
  • Occasional Live Feeders (with caution): While tempting, live feeders carry risks of disease and parasites. If you choose to use them, quarantine them first and ensure they are from a reputable source. Feeder fish like guppies or mollies can be gut-loaded to provide extra nutrition. Avoid goldfish or rosy reds, as they contain thiaminase, which can be harmful.
  • Insects: Crickets, mealworms, and superworms (from reputable pet stores, not wild-caught) can be offered as treats.

Feeding Frequency & Portions

Juvenile arowanas have a high metabolism and grow quickly, so they need to be fed more frequently than adults.

  • Juveniles (up to 12 inches): Feed 2-3 times a day, offering an amount they can consume within 2-3 minutes.
  • Sub-Adults (12-24 inches): Feed 1-2 times a day.
  • Adults: Once a day or every other day.

Always remove any uneaten food promptly to prevent water quality issues. Overfeeding is a common mistake that can lead to digestive problems and poor water quality.

Common Problems & Solutions for Arowana Fish in Small Tanks

Even with the best intentions and meticulous care, issues can arise. Knowing how to identify and address common problems with arowana fish in small tank environments is crucial for their survival and your peace of mind.

Fin Rot & Bacterial Infections

Cause: Often a result of poor water quality (high nitrates, ammonia, nitrites), stress, or physical injury.
Symptoms: Frayed, discolored fins, red streaks, white patches.
Solution: Immediately perform a large water change (50%). Increase aeration. Use a broad-spectrum antibiotic or antifungal treatment if symptoms persist after water quality improvement. Maintain pristine water conditions moving forward.

Droop Eye (DE)

Cause: A hotly debated topic among aquarists. Theories include diet (too much floating food), genetics, lack of adequate swimming space, or constant reflection in the tank glass causing the fish to look down.
Symptoms: One or both eyes appear to be permanently looking downwards.
Solution: Ensure a varied diet with sinking foods. Consider a bare bottom tank or a dark substrate. Reduce reflections by darkening the room or adding a background. Some aquarists advocate for placing a ping-pong ball on the surface to encourage upward gazing, but effectiveness varies. Prevention is better than cure, as it’s often irreversible.

Gill Curl

Cause: Primarily poor water quality, especially high nitrates or low oxygen. Can also be caused by rapid growth in a cramped tank.
Symptoms: The gill plate curls outwards, exposing the delicate gill filaments.
Solution: Improve water quality immediately with large water changes and ensure robust filtration and aeration. If caught early, it can sometimes reverse. In severe cases, surgical trimming by an experienced professional might be an option, but it’s risky.

Jumping

Cause: Arowanas are natural jumpers, especially when startled, stressed, or hunting.
Symptoms: Fish is found on the floor next to the tank.
Solution: As mentioned, a heavy, secure, tightly fitting lid is non-negotiable. Ensure there are no gaps for wires or equipment that the fish can squeeze through. This is one of the most common causes of arowana loss.

Aggression & Stress

Cause: Inadequate space, inappropriate tank mates, poor water quality, or sudden changes in environment.
Symptoms: Hiding, darting, rubbing against decor, refusal to eat, faded colors, fin nipping (if with tank mates).
Solution: Ensure the tank is appropriately sized for its current stage. Avoid keeping arowanas with aggressive or fin-nipping fish. Choose tank mates carefully (e.g., large, peaceful bottom dwellers if the tank is very large). Maintain stable water conditions and a consistent routine.

Long-Term Care and the Future of Your Arowana

Keeping an arowana, even a juvenile in a “small” tank, is an exercise in planning. The temporary nature of this initial setup is what makes eco-friendly arowana fish in small tank care truly ethical.

The Upgrade Plan: Crucial for Growing Fish

This cannot be stressed enough: your juvenile arowana will grow, and it will grow quickly. Your 75-gallon or 125-gallon tank will become too small, usually within 6-12 months. You absolutely must have a plan for an upgrade.

  • Budget for a Larger Tank: Start saving and researching large tanks (200+ gallons, ideally 300-500+ gallons for an adult Silver Arowana) from day one.
  • Space Considerations: Do you have the physical space and floor support for such a large aquarium?
  • Filtration Upgrade: Plan for increased filtration capacity for the larger tank.

Failing to upgrade your arowana to an appropriately sized tank as it grows is where the ethical line is crossed. A stunted arowana is a stressed, unhealthy arowana.

Ethical Considerations & Rehoming

What if, despite your best intentions, you realize you cannot provide a suitable permanent home for your adult arowana?

  • Plan Ahead: Research local fish clubs, reputable fish stores, or online forums that facilitate rehoming large fish.
  • Never Release into the Wild: This can introduce invasive species and diseases, harming local ecosystems.
  • Be Honest with Yourself: If you’re unsure you can commit to a large adult arowana, it’s better to admire them from afar or choose a smaller, more manageable species.

Being prepared for the long haul is a hallmark of truly sustainable arowana fish in small tank keeping.

Frequently Asked Questions About Keeping Arowana Fish in Small Tanks

How big of a tank does a juvenile Arowana need?

For a juvenile Silver Arowana (up to 12-15 inches), a minimum of 75-90 gallons is recommended, with a strong preference for a 125-gallon tank or larger. The tank should be at least 4-5 feet long to allow for adequate swimming space. This is a temporary setup, requiring an upgrade as the fish grows.

Can a Silver Arowana live its whole life in a 75-gallon tank?

Absolutely not. A Silver Arowana can grow to 3 feet or more in length. Keeping an adult Silver Arowana in a 75-gallon tank would severely stunt its growth, lead to significant health issues, and cause extreme stress. It is considered inhumane. A mature Silver Arowana requires a tank of 200-300 gallons minimum, with 500+ gallons being ideal.

What are the signs of stress in an Arowana in a small tank?

Signs of stress include erratic swimming, constant rubbing against the tank sides, faded coloration, clamped fins, refusal to eat, hiding excessively, or rapid breathing. These often indicate poor water quality, inadequate space, or inappropriate tank mates.

Is it cruel to keep an Arowana in a smaller tank?

It is not inherently cruel to keep a *juvenile* arowana in an appropriately sized “small” tank (e.g., 75-125 gallons) as a temporary measure, provided you are committed to excellent water quality, proper feeding, and have a definite plan for a much larger upgrade tank as it grows. It becomes cruel if the fish is left to grow in a tank that is too small for its adult size, leading to stunting and suffering.

What are the benefits of arowana fish in small tank care (for juveniles)?

Keeping a juvenile arowana fish in small tank environments (relative to their adult size) allows hobbyists to observe their fascinating growth and behavior more closely during their most active developmental stage. It also makes initial setup and maintenance more manageable for aquarists who may not immediately have the space or budget for a massive adult arowana tank, giving them time to prepare for the inevitable upgrade. It offers an entry point into caring for these magnificent fish responsibly.

Conclusion

Bringing an arowana into your home is a truly rewarding experience, offering you the chance to observe one of nature’s most magnificent freshwater predators. While the idea of an arowana fish in small tank setup might initially seem daunting or even ill-advised, we hope this comprehensive guide has shown you that, with dedication and foresight, it’s entirely possible to provide a thriving environment for a juvenile arowana.

Remember, the core principles are always the same: impeccable water quality, a diverse and nutritious diet, vigilant observation, and most importantly, a steadfast commitment to providing an adequately sized home for every stage of your fish’s life. Embrace the journey of learning and growing with your fish, and you’ll find immense satisfaction in its health and vibrancy. With these arowana fish in small tank care guide principles, you’re now equipped to embark on a successful and ethical adventure into the world of arowana keeping. Happy fishkeeping!

Howard Parker
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