Asian Arowana Tank Setup: Complete Aquarium Guide

A detailed setup guide for Asian Arowana aquaria including tank size, ideal water parameters, filtration, decor, cycling, and compatible tankmates tailored to this species' needs.

Introduction

Setting up a tank for an Asian Arowana requires careful planning, because the species grows large, produces significant waste, and has behavioral needs (jumping, surface orientation, territoriality). This guide covers everything from recommended aquarium dimensions to water chemistry, filtration systems, substrate and decoration choices, cycling a new system, and considerations for tankmates specific to Asian Arowana.

Tank size and shape

• Juveniles: a minimum of 150–200 gallons (approx. 570–760 liters) depending on growth rate; a long tank is better than a tall or narrow one.
• Subadults: 250–400+ gallons (950–1500 liters) is recommended as fish approach 50–70 cm.
• Adults: serious hobbyists and commercial facilities often use 1000+ liter systems or ponds; adult Asian Arowana commonly need 300–500+ gallons for single specimens in home aquaria to provide adequate turning space.

• Long footprint (wide and long) rather than tall; Asian Arowana swim horizontally near the surface and need long open spaces.
• Sturdy construction (glass or acrylic) rated for heavy water volume and the strength of pumps/filtration.
• Secure, fitted lid to prevent jumping (Asian Arowana are notorious jumpers).

Water parameters

• Temperature: 26–30°C (78–86°F) for optimal metabolism and digestion. Avoid rapid temperature swings.
• pH: Slightly acidic to neutral commonly recommended (6.0–7.5) depending on the origin of the stock. Consistency is more important than a specific pH within this range.
• Hardness: Soft to moderately hard water is acceptable; avoid abrupt changes. Aim for general hardness (GH) and carbonate hardness (KH) that provide stability.
• Ammonia and nitrite: 0 ppm. Nitrate: keep below 20–40 ppm for sensitive specimens.

Filtration and water movement

Asian Arowana demand powerful filtration because of their size and carnivorous diet. A multi-stage system is best.

Recommended filtration

• Sump systems or large canister filters with substantial mechanical, biological, and chemical filtration capacity.
• High-flow pre-filtration to remove solids before biological media.
• Robust biological media (bio-balls, ceramic rings, sponge) to maintain nitrifying bacteria.
• Protein skimming is not typical for freshwater setups but mechanical removal of organics and heavy water changes are critical.

• Moderate flow is ideal—avoid extremely high turbulence at the surface that can stress the fish but provide adequate circulation to oxygenate the water and move detritus to filters.
• Ensure good surface agitation for gas exchange but avoid strong upward currents that can cause jumping or disorientation.

Cycling the tank

• Cycle the system fully before introducing an Asian Arowana. Use fishless cycling with ammonia additions or established media from a mature tank to seed bacteria.
• Confirm 0 ppm ammonia and nitrite and stable nitrate production before stocking.
• For large tanks, seed biological media from established systems if available, and monitor parameters closely for several weeks after initial stocking.

Substrate, decor, and plants

Substrate

• Fine sand or smooth gravel are preferred; avoid sharp or rough substrates that can cut delicate belly or fins during activity.
• Some keepers use bare-bottom tanks for ease of cleaning with large Arowana.

• Keep decor minimal to maximize open swimming space. Use a few large, smooth pieces of driftwood or rocks rounded and arranged to create sight-line breaks and resting zones.
• Avoid overcrowding with tall fragile plants or spiky decorations that can damage fins.

• Use large, hardy plants (Anubias anchored to wood, Java fern attached to rocks) or artificial plants. Live plants can help water quality but may be uprooted by a large Arowana.
• Floating plants can diffuse light and provide shaded areas, which Arowana appreciate.

Lighting and temperature control

• Moderate lighting mimics natural conditions. Avoid bright, intense lighting that encourages jumping or stress.
• Use reliable heaters sized appropriately for tank volume with a backup thermostat or controller. Consider redundancy for large, valuable specimens.

Tankmates: compatibility and caution

Asian Arowana are apex predators and are both territorial and aggressive. Tankmate choices are limited and must be large, robust, and non-provocative.

Potential compatible tankmates (with reservations)

• Large plecos (e.g., Hypostomus species) for bottom-dwelling algae control—ensure pleco size is large and they are well-armored.
• Very large, peaceful catfish species (species-specific compatibility must be confirmed); avoid small catfish that can be eaten.
• Giant gourami or other large, robust cichlids only in very large tanks and with carefully observed introductions.

• Small fish of any kind (likely to be eaten).
• Highly territorial or fin-nipping species that provoke aggression.
• Fragile or slow-moving species likely to be harassed.

• Introduce tankmates when fish are young and in a very large, neutral tank if you plan to keep multiple large species; watch for dominance behavior.
• Always quarantine tankmates before introduction and remain ready to remove them at the first sign of aggression.

Lid and safety considerations

• Secure lids are mandatory. Asian Arowana will jump to extremes and can injure themselves or die by jumping out.
• Light-weight mesh or poorly fitting lids are inadequate—use heavy duty glass or acrylic covers with sealed edges.

Maintenance plan for large systems

• Use an efficient water-change schedule (20–30% weekly) and consider automating top-ups and dosing for very large systems.
• Maintain redundant filtration (two pumps, multiple filter paths) to avoid catastrophic failures.
• Establish relationships with professionals for lifting, moving, or large water exchanges when needed.

Legal and conservation notes

• Asian Arowana (Scleropages formosus) have international trade restrictions under CITES in many jurisdictions. Ensure you have appropriate permits and documentation for ownership and breeding.
• Sourcing captive-bred specimens from reputable breeders reduces pressure on wild populations and is often legally required in regulated regions.

Conclusion

A proper Asian Arowana tank prioritizes length, open swimming space, top security, stable water chemistry, and powerful filtration. Thoughtful selection of tankmates, minimal but sturdy decor, and a consistent maintenance regime are essential. Because these fish are large and valuable, planning for redundancy and professional support is a wise investment.

FAQ

Q: What is the minimum tank size for an adult Asian Arowana?

Q: Do Asian Arowana need a lid?

Q: Can I keep live plants in an Asian Arowana tank?

Q: Is a sump necessary for an Asian Arowana tank?

Q: Are backyard ponds better for Asian Arowana?

Frequently Asked Questions

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