Silver Arowana Care Guide 2026: Tank Size, Diet & Expert Tips

The Silver Arowana (Osteoglossum bicirrhosum) is one of the most commanding freshwater fish you can add to a home aquarium. With its armored silver scales, distinctive black lateral stripe, and that unmistakable drawbridge mouth snapping at the surface, the Silver Arowana has earned its place as the pinnacle of the monster fish hobby. These ancient predators have been hunting the same way for over 150 million years, their upward-facing eyes scanning the water's surface for insects, small fish, and anything else that dares drift too close.

Keeping a Silver Arowana is not a casual undertaking. This is a fish that demands a 250-gallon tank, powerful filtration, and a secure lid that can withstand a 3-meter jump. They grow at roughly 2 inches per month during their first year, and they will eat anything that fits in that oversized mouth. Most captive specimens eventually develop drop eye, a frustrating condition that reminds keepers how difficult it is to replicate their natural Amazonian habitat in glass boxes.

This silver arowana care guide cuts through the generic advice and gives you the real information you need. Whether you are evaluating if a Silver Arowana belongs in your home, planning your tank setup, or trying to understand why your fish is looking a bit off, this guide covers everything.

Silver Arowana: Species Summary

Scientific Name:	Osteoglossum bicirrhosum
Common name:	Silver Arowana, Bonytongue, Dragon Fish, Monkey Fish
Family:	Osteoglossidae
Origin:	Amazon River Basin and Orinoco River Basin in South America
Maximum size:	Up to 3 feet (36 inches) in length
Average Life span:	10 to 20 years in captivity
Habitat:	Freshwater (blackwater and whitewater tributaries)
Minimum Tank size:	250 gallons for adults
Temperature:	75 to 82 Fahrenheit
pH range:	5.0 to 7.5
Water Hardness:	1 to 8 dKH
Temperament:	Very aggressive and territorial
Care level:	Difficult - Expert Only
Diet:	Carnivorous

The Silver Arowana is one of several arowana species popular in the aquarium trade. While the Red Arowana faces severe CITES restrictions due to overharvesting, and the Jardini Arowana brings Australian-level aggression, the Silver Arowana remains the most accessible and commonly kept member of the Osteoglossidae family.

A healthy Silver Arowana has a streamlined, silver body with a pearlescent sheen. The scales lie flat and smooth, the fins are clear and undamaged, and the eyes are bright and upward-facing. Avoid fish with swollen abdomens, clamped fins, lethargy, or visible spots. The Silver Arowana is sensitive to water quality, so starting with a robust specimen gives you the best chance of success.

Silver Arowana: Appearance

The Silver Arowana has an elongated, laterally compressed body covered in large, bony scales. A distinctive black band runs from the snout to the base of the caudal fin, giving these fish one of their common nicknames: band fishes. The scales have an iridescent quality that catches light beautifully, which is a large part of their appeal in the aquarium trade.

Two dorsal fins run along the back, with the first noticeably taller than the second. The pectoral and ventral fins are thin and fragile. The forked tail fin provides propulsion for their explosive surface attacks. All these fins together give the Silver Arowana its distinctive silhouette.

Two sensory barbels extend from the tip of the upper jaw, contributing to the "Dragon Fish" nickname. These barbels detect vibrations at the water surface, helping the fish locate prey in murky conditions. The barbels are delicate and can be damaged by poor water quality or rough handling.

The most distinctive feature is the nearly vertical mouth that opens like a drawbridge. This unique jaw structure creates powerful suction that lets Silver Arowanas inhale prey in milliseconds. Large eyes positioned for upward vision complete the picture of a specialized surface predator. Their scales are large, bony, and extremely tough, providing genuine protection against predators in the wild.

Silver Arowanas are one of the few fish that can look straight up and see what is happening above the water surface. This aerial vision helps them spot low-flying insects and small birds resting on overhanging branches, which they occasionally catch in the wild.

Silver Arowana: Origin And Physical Distribution

Silver Arowanas come from the Amazon River Basin and Orinoco River Basin in South America. They are found throughout Brazil, Peru, Colombia, Venezuela, Ecuador, Bolivia, Guyana, Suriname, and French Guiana. Within these vast river systems, they inhabit both blackwater tributaries stained dark with tannins and clearer whitewater sections.

In their natural habitat, Silver Arowanas prefer slow-moving waters, flooded forests, and shallow lagoons. They are primarily surface dwellers, patroling just beneath the water's skin where their upward-facing eyes give them an advantage. During the Amazon flood season, which typically peaks around July, they move into flooded forest areas to feed and breed.

While wild populations in South America remain healthy, Silver Arowanas have been widely introduced to aquariums worldwide. Unlike the endangered Asian Arowana, Silver Arowanas are not restricted by international trade regulations, making them the most accessible arowana species for hobbyists everywhere.

Silver Arowana: Adult Size, Growth Rate, And Life Expectancy

Silver Arowanas grow quickly, and that surprises many first-time keepers. Under optimal conditions, juveniles grow approximately 2 inches per month during their first year. A 4-inch juvenile purchased in spring can reach 18 to 24 inches by the following spring. That kind of growth rate means your tank requirements will escalate faster than you expect.

Most adult Silver Arowanas in home aquariums reach 24 to 30 inches. In large indoor ponds, they can reach the full 36-inch potential. They can weigh up to 5 pounds at maturity. Growth slows after the first two years but continues gradually throughout their lifespan.

With proper care, Silver Arowanas live 10 to 20 years in captivity. Some documented specimens have exceeded 20 years. This is not a fish you buy on impulse. It is a multi-decade commitment that should be taken as seriously as adopting a parrot or other long-lived companion animal.

Silver Arowana: Behavior And Temperament

Silver Arowanas are aggressive predators that sit at the top of the freshwater food chain in their native habitat. They are territorial and will defend their space against anything they view as either prey or threat. This is not a community fish by any reasonable definition, and tank mate selection requires extensive research and caution.

The jumping ability of Silver Arowanas cannot be overstated. These fish can launch themselves 3 meters (nearly 10 feet) out of the water to catch insects or escape perceived threats. In captivity, a loose tank lid means a dead fish on your floor within seconds. A secure, weighted lid is not optional; it is essential equipment.

Silver Arowanas are messy eaters that generate significant bioload. They often tear food into pieces and leave scraps that decompose rapidly in the warm aquarium water. Daily removal of uneaten food is critical for maintaining water quality and preventing ammonia spikes.

Temperament varies between individuals. Some Silver Arowanas become surprisingly tame, recognizing their owners and accepting food from fingertips. Others remain skittish and prone to bolting at sudden movements. Poor water conditions and inappropriate tank mates increase stress and can make even a hand-tame fish aggressive.

Silver Arowana: Sexing And Breeding

Determining the sex of Silver Arowanas is difficult even for experienced breeders. The most reliable indicators involve fin shape and body morphology once fish reach sexual maturity at 2 to 3 years of age. Males typically have longer, more pointed dorsal and anal fins. Females tend to have a rounder, fuller body shape, particularly when carrying eggs.

Breeding Silver Arowanas in home aquariums is extremely rare and generally not recommended. These fish become violently aggressive toward each other when breeding, and serious fights can result in severe injuries or death. If breeding is attempted, provide plenty of hiding spots and ensure both fish are well-fed to minimize aggression.

When spawning does occur, the male carries the fertilized eggs in his mouth for up to 50 days. This mouthbrooding behavior protects the developing fry from predators. After hatching, the fry remain near the male briefly before becoming free-swimming. Remove the parents immediately, as Silver Arowanas are known to eat their own offspring.

Fry require small live foods such as brine shrimp, bloodworms, daphnia, and microworms. Feed them multiple times daily and separate them by size to prevent larger fry from cannibalizing smaller siblings. Growth is rapid under good conditions, and fry will soon accept larger food items.

Silver Arowana: Food & Diet

Silver Arowanas are obligate carnivores that evolved to hunt at the water's surface. Their diet in the wild includes insects, small fish, crustaceans, amphibians, and occasionally small birds or mammals near the water. The specialized drawbridge mouth and upward-facing eyes are adaptations for this surface-hunting predatory lifestyle.

In captivity, provide a varied diet that includes high-quality carnivore pellets as a staple. Floating pellets work best because they encourage the natural surface-feeding behavior that keeps Silver Arowanas mentally and physically healthy. Supplement with frozen foods like shrimp, tilapia, and silversides.

Silver Arowana: Diet And Nutrition In Captivity

A varied diet keeps Silver Arowanas healthy and enhances their coloration. Quality carnivore pellets should form the foundation, supplemented with earthworms, crickets, shrimp pieces, and fish fillets. Occasional feeder fish are acceptable but should come from reliable sources to avoid introducing parasites.

Baby Silver Arowanas under 4 inches are notoriously difficult to feed. They often refuse pellets initially and require live foods like brine shrimp or bloodworms. Avoid giving insects like crickets and mealworms until the fish is firmly established on prepared foods. Varied diets of small meaty pieces support the rapid 2-inch-per-month growth rate that juveniles experience.

Vitamin supplementation fills nutritional gaps, especially for fish on primarily frozen diets. Liquid vitamins added to food before feeding support immune function, scale health, and coloration. A well-nourished Silver Arowana is more resistant to disease and more active in the aquarium.

Feeding Frequency

Juveniles under 8 inches should be fed 2 to 3 times daily to support their explosive growth. Offer only what they can consume within a few minutes to avoid leaving excess food to decompose. Adults can be fed once or twice daily, with portion sizes adjusted based on the individual fish and food type.

Different Feeding Methods

Most keepers simply drop food onto the water surface, allowing the Silver Arowana to hunt it down naturally. A feeding ring keeps floating food contained and encourages the fish to swim through the ring to reach its meal, providing exercise. Some keepers use feeding tongs to offer food directly, which also allows close observation of the fish during feeding.

Hand feeding can help tame a Silver Arowana over time. Approach the tank slowly and consistently, letting the fish learn that your presence means food. With patience, many Silver Arowanas will eventually take food directly from fingers, though this should always be done with caution given the sharpness of their teeth.

Silver Arowana: Care Requirements

Tank Parameters

Silver Arowanas require aquariums that match their adult size, not their current size. A minimum of 250 gallons is required for a single adult, though 300 gallons or larger is strongly recommended. The tank must be wide enough for the fish to turn around comfortably; experts recommend at least 4 feet of width and 7 feet of length for a mature specimen.

Height matters because Silver Arowanas swim near the surface and need room to maneuver without damaging their fins. A tank that is too shallow contributes to drop eye development, as the fish spends too much time looking downward. Aim for tanks at least 24 inches deep for adults.

Juveniles under 6 inches can start in 75-gallon tanks, but be prepared to upgrade within 6 to 12 months. The 2-inch-per-month growth rate catches many owners off guard, and fish kept in undersized tanks suffer stunted growth, stress, and physical deformities.

Tank Lid Security (Critical Warning)

Silver Arowanas can jump 3 meters (approximately 10 feet) vertically when startled or hunting. This is not an exaggeration or rare occurrence; it is a fundamental behavioral trait that every keeper must account for. A loose or lightweight tank lid is an invitation to disaster.

Use a heavy, custom-fitted lid that cannot be displaced when the fish launches itself at the cover. Glass or acrylic canopies with clamping mechanisms work better than simple floating lids. Check the lid security every time you open the tank, and never leave the tank uncovered even for a moment during maintenance.

Many experienced keepers add secondary barriers like wire mesh over the tank as insurance. The cost of a secure lid setup is trivial compared to losing a fish that required years of care and potentially hundreds of dollars to acquire.

Water Parameters

Silver Arowanas need clean, well-aerated water with parameters matching their Amazonian origins. Temperature should be maintained between 75 and 82 degrees Fahrenheit using reliable heaters. The pH should range from 5.0 to 7.5, with 6.0 to 7.0 being optimal. Water hardness should stay between 1 and 8 dKH.

Avoid stagnant water. Silver Arowanas need active surface agitation for proper gas exchange. They have a specialized swim bladder that allows them to gulp air at the surface, which assists with buoyancy in their natural floodplain habitat. Poorly oxygenated water causes stress and makes them susceptible to disease.

Water Changes

Weekly water changes of 25 to 30 percent are the standard recommendation for Silver Arowana tanks. This volume maintains water quality by diluting nitrates and replenishing minerals while avoiding the stress of larger changes. Always treat new water with a quality water conditioner to remove chlorine and chloramine.

For juveniles in smaller tanks, some experienced keepers recommend 25 to 30 percent water changes every 3 to 4 days due to the higher bioload relative to tank volume. Invest in a gravel vacuum to remove debris from the substrate during water changes.

Filtration Requirements

Powerful filtration is mandatory for Silver Arowana tanks. These large predators produce significant waste that quickly degrades water quality. Canister filters rated for 2 to 3 times the tank volume provide adequate mechanical, chemical, and biological filtration. The Fluval FX4 and similar high-capacity filters are popular choices.

Clean or replace mechanical filter media monthly, but preserve beneficial bacteria by rinsing media in old tank water rather than tap water. Never replace all filter media simultaneously, as this can crash the nitrogen cycle and cause dangerous ammonia spikes.

Substrate And Gravel

Fine gravel or sand makes an appropriate substrate for Silver Arowana tanks. Dark colors help these fish feel secure and display their silver coloration best. Avoid sharp-edged substrates that could damage delicate barbels during feeding. A gravel vacuum is essential for removing accumulated debris.

Aquascaping

Silver Arowanas prefer open swimming spaces over decorated environments. Place plants and decorations along the tank's perimeter, leaving the center area clear. Driftwood, smooth rocks, and hardy plants like anubias or java fern add visual interest without impeding movement. Floating plants can provide security for skittish juveniles.

Some keepers use bare-bottom tanks to simplify maintenance, since Silver Arowanas produce enough waste that substrate management becomes burdensome. Bare-bottom tanks also make it easier to spot and remove uneaten food.

Ammonia And Nitrates Level

Test ammonia and nitrate levels weekly using a liquid test kit. Ammonia should always be zero parts per million; any detection indicates a filtration problem, overfeeding, or overstocking. Nitrites should also remain at zero, while nitrates should stay below 20 parts per million.

Elevated ammonia and nitrites cause stress, gill damage, and make Silver Arowanas vulnerable to disease. In severe cases, they can be fatal. Prevention through proper filtration, feeding management, and regular water changes is far easier than treating a crisis.

Lighting And Heating Requirements

Position the tank in a room with consistent ambient temperature, away from direct sunlight, windows, and air conditioning vents. Use reliable aquarium heaters rated for your tank volume, with backup units recommended for larger setups. Silver Arowanas do not require specialized lighting, but they benefit from consistent day-night cycles.

Turn off tank lights at night to allow natural rest periods. Excessive lighting promotes algae growth and can stress Silver Arowanas, increasing their jumping tendency. If you want to observe your fish in low light, use a dim blue moonlight fixture rather than bright white lighting.

Water Test Kits

Keep a freshwater test kit on hand at all times. Liquid test kits for ammonia, nitrite, nitrate, pH, and hardness provide more accurate readings than strip tests. Test weekly and any time the fish show signs of distress or unusual behavior. Early detection of water quality problems prevents catastrophic events.

Transportation And Handling

Transport Silver Arowanas in large, breathable bags or reinforced plastic totes. The container must be large enough for the fish to orient itself properly; cramped conditions cause scale and fin damage. For adults, plastic totes often work better than fish bags, which can tear under the weight and strength of a large arowana.

When handling is necessary, support the body from underneath with one hand while cradling the head with the other. These fish are strong and slippery, and improper handling can injure both fish and handler. Avoid handling whenever possible; use nets or containers for movement instead.

Silver Arowana: Potential Diseases

Silver Arowanas are susceptible to several common freshwater diseases, particularly when water quality suffers or stress weakens their immune systems. Watch for these conditions and treat promptly at the first signs of trouble.

• Ich (White Spot Disease): Parasitic infection causing white spots, flashing, and clamped fins. Treat with elevated temperature and commercial ich medications following package directions.
• Flukes: External parasites that attach to gills, skin, and fins, causing irritation and secondary infections. Visible as tiny moving dots on the body.
• Velvet: Parasitic infection producing a golden or rust-colored dusting on the skin. Often accompanies poor lighting and stress.
• Hole in the Head Disease: Bacterial infection creating pits or holes in the head area. Often linked to poor nutrition and inadequate water quality.
• Fin Rot: Bacterial infection causing ragged, deteriorating fins. Usually secondary to physical injury or environmental stress.

Drop Eye Disease

Drop eye disease is the most commonly discussed health issue among Silver Arowana keepers and the most misunderstood. The condition causes one or both eyes to point permanently downward, as if the fish is looking at the tank floor. This is not a bacterial or parasitic infection; it is a structural deformity linked to environmental factors and genetics.

Forum discussions among experienced keepers suggest drop eye may result from keeping Silver Arowanas in tanks that are too shallow or too small. When a fish cannot swim upward freely and spends time looking down at tank decorations or reflections, the muscles supporting the eye can weaken or develop abnormally. Some bloodlines seem more susceptible than others.

Prevention is the best strategy. Provide a tank at least 24 inches deep with minimal bottom decorations. Use dark gravel or tank mats to reduce visual interest below. Maintain excellent water quality, as chronic stress contributes to developmental problems. Some keepers raise the water level to within an inch of the tank lid, forcing the fish to look upward constantly.

Once established, drop eye is rarely reversible. Some early-stage cases respond to exercise techniques using food to train upward eye movement, or vitamin E supplementation. Severe or long-standing cases are permanent. The fish can often live a full, healthy life with mild drop eye if water quality remains high.

The uncomfortable truth acknowledged across arowana forums is that nearly all Silver Arowanas in aquariums develop some degree of eye droop. Pond-raised specimens fare better due to greater depth and natural upward-looking behavior. This is one reason serious hobbyists transition adult Arowanas to indoor ponds when possible.

Silver Arowana: Preventing Diseases

Disease prevention centers on water quality and stress reduction. Maintain zero ammonia and nitrite, keep nitrates below 20 ppm, and perform consistent 25 to 30 percent weekly water changes. Quarantine all new fish for at least 30 days before introducing them to the main tank.

A varied, nutritious diet supports the immune system. Feed high-quality foods and consider vitamin supplements during stressful periods such as tank transfers. Avoid overcrowding, which increases aggression and water quality challenges.

Silver Arowana: Treatments And Medications

Common medications include metronidazole and praziquantel for parasites, and antibiotics for bacterial infections. Follow package directions carefully, as overdosing can harm fish. Some medications are harsh and can stress Silver Arowanas further, so always consider whether improved water quality alone might resolve the issue.

Consult an aquatic veterinarian for serious or persistent illness. Many fish medications require exact dosing that varies by individual fish, and some treatments can do more harm than good if misapplied.

Silver Arowana: Tank Mates

Finding suitable tank mates for a Silver Arowana is one of the most challenging aspects of keeping this species. The fundamental rule is brutal in its simplicity: anything small enough to fit in the mouth will become food. This includes fish you might assume are safe.

Silver Arowanas should be housed with large, robust fish that can tolerate their aggression. Even then, conflicts occur as the Silver Arowana grows larger. Never house Silver Arowanas with other arowana species; the aggression differences make violent encounters virtually guaranteed.

Potential tank mates must be fast-moving and capable of defending themselves. Some keepers have success with the following:

• Tiger Oscar
• Red Tail Shark
• Green Terror Cichlid
• Jewel Cichlid
• Fire Eel
• Sailfin Pleco
• Bumblebee Catfish
• Tiger Shovelnose Catfish

Tank mate compatibility depends on tank size, individual fish personalities, and how the fish were raised. What works in one setup may fail in another. Always have a backup plan if aggression becomes a problem.

How Many Silver Arowana Can Be Kept In One Tank?

Keeping multiple Silver Arowanas together requires either an enormous custom aquarium or an outdoor pond. These fish are territorial and will fight aggressively when space is limited. In tanks smaller than 500 gallons, keeping more than one is extremely risky.

Some keepers report success with multiple Silver Arowanas in very large settings where each fish can establish its own territory. The key is providing enough physical separation through structure and space that individuals rarely encounter each other. Even then, occasional conflicts are inevitable.

Advantages Of Having Silver Arowana In Your Tank

• Silver Arowanas are strikingly beautiful fish that serve as the centerpiece of any large display aquarium
• In some cultures, Silver Arowanas are believed to bring good luck and prosperity to the household
• They are active surface swimmers that are fascinating to watch
• With proper care, they can live for 15 to 20 years, providing long-term companionship
• They represent the pinnacle of freshwater fishkeeping achievement

Disadvantages Of Having Silver Arowana In Your Tank

• Silver Arowanas require massive tanks and powerful filtration systems
• They are aggressive and will eat most tank mates
• They are jumpers that can kill themselves by launching onto the floor
• Fast growth means expensive tank upgrades needed sooner than expected
• The 15 to 20 year commitment surprises many first-time keepers
• Drop eye and other deformities are common in captive specimens

Silver Arowana: Are You Up For It?

Before you bring home a Silver Arowana, be honest with yourself about what you are signing up for. This fish will be part of your life for 15 to 20 years. It will require hundreds of dollars in tank equipment, ongoing costs for food and maintenance, and significant floor space in your home.

The Silver Arowana is not a fish for beginners. It demands consistent water quality, careful feeding management, and constant attention to potential health problems. If you are still building your skills with freshwater tanks, consider starting with less demanding species and working toward an arowana later.

Forum discussions among experienced keepers reveal a common theme: people who succeed with Silver Arowanas planned for the commitment from the start. They researched tank requirements, understood the 2-inch-per-month growth rate, and set up their systems before the fish arrived. Impulse purchases and underestimates of space requirements lead to dead fish and disappointed keepers.

If you have the space, the budget, and the dedication to maintain 25 to 30 percent weekly water changes over years of ownership, a Silver Arowana can be incredibly rewarding. Just make sure you are ready for the responsibility before you take the plunge.

Conclusion

The Silver Arowana is not just a fish; it is a lifestyle commitment spanning two decades. These magnificent predators from the Amazon have specific needs that only dedicated keepers can meet. From the minimum 250-gallon tank requirement to the essential secure lid that prevents tragic escapes from their 3-meter jumping ability, every aspect of Silver Arowana care demands attention.

This silver arowana care guide has covered the essential information you need to understand the species and evaluate whether you are ready. The rapid 2-inch-per-month growth rate, the aggressive temperament, and the 10 to 20 year lifespan all factor into whether this is the right fish for your situation.

If you are serious about adding a Silver Arowana to your aquarium family, take time to set up the tank properly before you bring the fish home. Research water parameters, plan your filtration, and secure the lid. Your future Silver Arowana will thank you for it.

For more information on other arowana species, explore our Jardini Arowana care guide and learn about the critically endangered Red Arowana. Thank you for reading, and good luck with your Silver Arowana journey.