Silver Albino Arowana (Osteoglossum bicirrhosum) – 10–25cm Sizes

Decide whether you can house a giant surface fish

The Silver Albino Arowana (Osteoglossum bicirrhosum) is a freshwater member of the arowana family, Osteoglossidae, from South America’s Amazon basin, Rupununi and Oyapock rivers. FishBase records a maximum length of 90 cm. This is an advanced choice for a keeper who can provide a public installation or one of the very largest private aquaria, not an ordinary home community aquarium.

Its upturned mouth lets it capture prey above it while swimming from below. Wild fish are omnivorous generalised predators that eat other fish, terrestrial insects, aquatic invertebrates and fallen plant material. That feeding biology, the adult length and the need for a heavy, tightly fitting cover should shape the aquarium before the fish is selected.

Match the fish to the installation

Seriously Fish describes this species as suitable only for public installations or the very largest private aquaria. Make that long-term facility the first decision; colour, dispatch size and potential companions come afterwards.

Choose the dispatch size with the adult in mind

One purchase supplies one fish in the size chosen on the live size selector. The choices are labelled “10 - 15 cm” and “20-25 cm”. The size you select is the size supplied, not the adult size. Neither measurement should be used to infer the fish’s age, sex or life stage; plan both choices around the same 90 cm adult length.

Sex is guaranteed only when the selected option explicitly states male or female. This Silver Albino Arowana listing has no sex-guaranteed option.

Some gallery images have been digitally enhanced to improve image quality. They show the listed type of animal rather than guaranteeing the exact markings of the individual supplied, so natural colour and pattern can vary.

Use the selector for one decision only

• Choose 10 - 15 cm only if the aquarium, cover, filtration and feeding plan already suit the selected fish and its eventual adult requirements.
• Choose 20-25 cm only if the same long-term installation is ready and the larger dispatch measurement fits the planned stocking assessment.
• For either size, allow for the full adult length from the beginning rather than treating the first aquarium as the permanent endpoint.

Commit to the decisive care values

Keep this fish at 24–30°C, pH 5.0–7.5 and 2–15 dGH. The temperature is the overlap between FishBase’s recorded 24–30°C environment and the 20–30°C aquarium range from Seriously Fish; the pH and hardness ranges come from the latter’s species profile. Stability is obligatory, so choose a target within those ranges that the established system can hold consistently.

Provide a biologically mature, heavily covered installation with a high proportion of dissolved oxygen, moderate water movement and filtration able to manage a very large fish. Seriously Fish calls weekly water changes of 30–50% mandatory. It also describes a heavy, tightly fitting cover as essential because Osteoglossum species are prodigious jumpers.

OATA’s tankbuster guidance says an exceptionally large aquarium is required, often in excess of 500 litres, and that indoor heated ponds can be built to house these fish instead. Treat that figure as broad group planning context rather than the endpoint for this species; the applicable standard here remains a public installation or one of the very largest private aquaria.

Make the commitment before choosing the fish

• Plan around a 90 cm adult, not the dispatch measurement.
• Use a secure cover that the fish cannot dislodge.
• Establish biological filtration before introduction.
• Confirm that temperature, pH and hardness remain inside the stated ranges.
• Decide how the adult installation will be maintained every week.

If you are comparing the commitment with other specialist freshwater animals, browse the loaches and oddballs collection without treating another species as an automatic substitute.

Build a covered, oxygen-rich installation

Secure the top first

Fit a heavy, tightly closing cover across the aquarium. Seriously Fish identifies this as essential because Osteoglossum species are prodigious jumpers. Check every section used for feeding, cables, pipework and filter returns so the completed cover remains tightly fitted after the equipment is installed.

Some floating or overhanging vegetation or branches are appreciated. Use those features without compromising the cover or preventing the fish from reaching its surface-feeding area. The layout should support the animal’s normal surface-oriented movement while retaining the cover that contains it.

Provide oxygen and controlled movement

A high proportion of dissolved oxygen and a moderate degree of water movement support this species. Seriously Fish says external filters, powerheads and airstones should be employed as necessary to provide that oxygen and movement. Select a combination that maintains oxygenation and movement throughout the installation without allowing filtration capacity to become the limiting factor.

Large fish create large quantities of solid waste. OATA notes that several large aquarium filters, or even a pond filter, may be needed for tankbusters. Filter choice therefore has two jobs: maintain the biological process that handles dissolved waste and physically remove the solids produced by feeding and normal activity.

Mature the system before introduction

Never add this fish to a biologically immature aquarium. Establish the biological filter, test it and confirm that ammonia and nitrite are both zero before introduction. Our first tropical aquarium guide explains the preparation and maturation process, but the scale of this installation must still match a 90 cm surface fish.

Complete the cover, filtration, aeration, water movement and maintenance access before the animal arrives. A smaller dispatch measurement does not reduce the need for mature filtration or justify postponing the adult plan.

Hold stable water inside the species ranges

Set a repeatable target

Maintain 24–30°C, pH 5.0–7.5 and hardness of 2–15 dGH. Choose stable values inside all three ranges rather than moving repeatedly between their limits. Seriously Fish says stable water conditions are obligatory for this animal’s well-being, so consistency is part of the care requirement rather than an optional refinement.

The 24–30°C temperature instruction is the overlap between FishBase’s recorded environmental range and Seriously Fish’s aquarium range. Use the water matcher to compare measured aquarium values with those targets, and read the water chemistry guide for the role of each routine test.

Control nitrogen waste

Keep ammonia at zero mg per litre and nitrite at zero mg per litre. OATA’s very-large-fish sheet gives those values as group guidance and says nitrate should not exceed 20 mg per litre above the normal tap-water level. Test at least weekly, using the result to judge whether filtration, feeding and the water-change routine are keeping pace with the fish’s waste.

Maintain good oxygenation alongside the chemical targets. FishBase notes an ability to adapt to low-oxygen environments in nature, but the aquarium instruction from Seriously Fish is to provide a high proportion of dissolved oxygen and moderate movement.

Protect the biological filter

Make biological filtration non-negotiable

The RSPCA’s aquarium welfare guidance explains that fish release toxic ammonia and that a working biological filter supports bacteria which convert ammonia to nitrite and then to the safer nitrate. This fish must therefore live in a mature system with a well-established filter, not an installation that is still building biological capacity.

Scale filtration to both the animal and its feeding. OATA warns that large fish produce substantial quantities of solid waste and may require several large filters or a pond filter. A nominal filter rating is only one part of the decision: the system must maintain zero ammonia, zero nitrite, controlled nitrate and clear pathways for water movement.

Check the system every week

• Test ammonia and nitrite at least once a week and require both to read zero mg/l.
• Compare aquarium nitrate with the normal tap-water level and keep the difference within 20 mg/l.
• Inspect filters for blockages that could restrict flow or reduce waste removal.
• Confirm that powerheads, airstones and filter returns continue to provide oxygenation and moderate movement.
• Remove solid waste during the water change rather than leaving it to break down.

Clean without stripping the bacteria

When filter media needs cleaning, rinse it lightly in aquarium water removed during a partial water change, never under the tap. Chlorine or chloramine may kill the established bacterial population. Treat replacement tap water with a suitable conditioner before it enters the aquarium.

Respond to a non-zero ammonia or nitrite result as a filtration and husbandry warning. Check for blocked media, uneaten food, accumulated solids and recent increases in feeding, then complete the conditioned water change and retest. Do not add further livestock while the biological filter is failing to hold both readings at zero.

Feed the recorded predator-omnivore diet

Build the diet around suitable animal foods

This is a generalised predator and omnivore. Seriously Fish reports that wild specimens eat other fish, terrestrial insects, aquatic invertebrates and plant material such as fallen nuts and fruits. FishBase also records a tendency to take fish at the surface. Use foods that fit that biology rather than relying on one dried product.

For a smaller specimen, suitable examples include bloodworm, small earthworms and chopped prawn. Adults will accept strips of fish flesh, whole prawns or shrimp, mussels, live river shrimp and larger earthworms. Match each item to the fish’s ability to take it cleanly, and vary the selection rather than turning one food into the entire diet.

Crickets and other suitable insects may also be used. Seriously Fish advises filling their stomachs first with fish flakes or vegetable matter before offering them to the arowana. Floating dried foods can form a limited part of the rotation, but the recorded diet supports a varied mixture of fish, invertebrate and insect foods as the main approach.

Control portions and waste

Feed once a day and offer only what the fish can consume within a few minutes. That frequency and portion rule comes from OATA’s tankbuster sheet as group guidance. It controls both intake and the uneaten food that would otherwise break down into toxic waste.

1. Offer a small first portion that suits the fish’s mouth and surface-feeding behaviour.
2. Add more only while the food is being taken promptly.
3. Stop within a few minutes rather than extending the session.
4. Remove food that remains uneaten so it does not decay in the aquarium.
5. Check the next ammonia, nitrite and nitrate readings before deciding that the portion is sustainable.

Do not feed mammalian or avian meat such as beef heart or chicken. Seriously Fish warns that predatory fish cannot properly metabolise some of the lipids these meats contain. Keep prawns, shrimp, mussels, earthworms, suitable fish flesh, insects and limited floating dried foods as the practical rotation.

Plan the aquarium around the adult size

Plan for 90 cm, the maximum total length FishBase records for this species. Seriously Fish records 80 cm standard length. Use 90 cm when deciding whether the installation can house the fish for life.

The 10 - 15 cm and 20-25 cm labels describe the fish at dispatch. They do not reduce the eventual space, filtration, cover or maintenance requirement, and they do not identify age or life stage. A smaller selection simply starts the same long-term commitment at a smaller measured size.

Use the adult facility as the test

OATA warns that many tankbusters grow very quickly and that an off-the-shelf aquarium is unlikely to meet their long-term needs. Secure the adult solution before relying on temporary accommodation. A large nominal litre figure alone does not replace the species guidance: Seriously Fish restricts this animal to public installations or the very largest private aquaria.

Review access for water changes, filter servicing and cover checks as part of the space plan. The aquarium is only workable when routine maintenance can be completed without weakening containment, oxygenation or biological filtration.

Follow the store acclimatisation steps

Prepare before the delivery day

Arrange for someone to receive the parcel because live fish must not be left unattended. The fish is hand-bagged in pure oxygen and placed in an insulated poly box, with a heat pack when the weather calls for one. A licensed live-animal courier carries the parcel, with tracking and the confirmed arrival date sent by email.

Before adding the fish, follow OATA’s introduction advice by checking that the aquarium is an appropriate size and that ammonia and nitrite are both zero. The aquarium must already be biologically mature, covered and operating within 24–30°C, pH 5.0–7.5 and 2–15 dGH.

Use the stated arrival sequence

1. For every delivery, start filming a short continuous unboxing video before the parcel is opened. Show the parcel still sealed with the outer box visible, record it being opened in one continuous take, and show the fish still inside the sealed bag before anything is disturbed. Open and inspect the parcel the same day it arrives; this video is required for a Live Arrival Guarantee claim under the delivery and Live Arrival Guarantee policy.
2. Float the bag in the aquarium for 20–30 minutes before releasing the fish.
3. Release the fish after floating, but never pour the bag water into the aquarium.

Close the heavy cover as soon as the fish is released, because Osteoglossum species are prodigious jumpers.

Observe the fish after release

OATA advises watching swimming behaviour, breathing, colour, temperament, physical appearance, body condition and interest in food. A fish settling into a new installation should be assessed against its own normal behaviour while the water remains stable and the cover remains secure.

Hanging at the surface in a way that differs from its normal surface-feeding movement, sitting on the bottom, erratic swimming, unusually fast or slow gill movement, a marked colour change, damaged fins, lost scales, spots, fluffy growths or refusal of food are reasons to test the water immediately and investigate the husbandry conditions.

Keep a weekly maintenance rhythm

Complete the essential weekly work

Change 30–50% of the aquarium volume every week. Seriously Fish treats that species-level water-change schedule as mandatory because stable conditions are obligatory. OATA’s broad tankbuster advice says to change 25% of the water at least once every week, so the 30–50% instruction is the applicable routine for this fish.

• Test temperature, pH, hardness, ammonia, nitrite and nitrate before the change.
• Siphon out accumulated solid waste while removing the old water.
• Treat replacement tap water with conditioner to remove chlorine or chloramine.
• Keep replacement conditions consistent with the established aquarium.
• Check filters for blockages and confirm that water movement and aeration remain effective.
• Rinse filter media lightly in removed aquarium water only when cleaning is needed.

Use daily observations as an early warning

Check swimming behaviour, breathing, colour, temperament, scales, fins, body condition and feeding response, then confirm the cover is still tightly closed. OATA highlights changes in each of these areas as possible early signs of a health or husbandry problem. The normal pattern for the individual fish is the useful baseline.

As soon as you are concerned about a health change, test the water first and contact us with the readings, the observed behaviour and clear details of the physical change. Do not allow a search for treatment to replace correction of ammonia, nitrite, oxygenation, filtration or unstable water conditions.

Review capacity at every weekly change

At each weekly change, compare the latest readings with zero ammonia, zero nitrite and nitrate no more than 20 mg/l above tap water. If waste rises between changes, review food portions, solid-waste removal and filter capacity. The target is a repeatable routine that still works as the fish becomes larger.

Screen every companion for predation and competition

Choose companions only when they are too large to swallow and the installation can support every animal at adult size. Seriously Fish describes this arowana as peaceful with animals too large to swallow, but its recorded diet includes fish and aquatic invertebrates. Anything that can be taken as prey should be treated as a predation risk.

Avoid aggressively territorial or very competitive species. They can challenge the arowana for space or food even when they are physically too large to swallow. Other surface-dwelling fish are also best avoided except in the very largest installations because they occupy the same part of the aquarium.

Apply the named examples cautiously

Run the full screening test

1. Compare the adult size of the candidate with the arowana’s mouth and 90 cm adult length.
2. Exclude anything that may be swallowed now or after the animals grow at different rates.
3. Exclude aggressive or highly competitive species.
4. Identify whether the candidate competes at the surface.
5. Confirm that the installation can maintain oxygenation and water quality with the added waste.
6. Observe feeding and behaviour after introduction rather than assuming a named group is automatically compatible.

Compatibility depends on the sizes and behaviour of the actual animals and the scale of the installation. Ask us when you have the aquarium dimensions, measured water values and proposed companions, so the stocking assessment can address the whole system rather than one species name.

Manage its own kind as a separate risk

Plan around one Silver Albino Arowana unless a very large installation has been assessed specifically for multiple adults. Seriously Fish reports that this species can become aggressive towards its own kind when space is limited. Even in larger systems, a group forms a distinct pecking order.

Do not treat two fish of similar dispatch size as an automatically stable pair. The same adult-size test applies to each animal, and apparent tolerance does not remove the need to watch aggression, feeding access and changes in behaviour as the fish develop.

Require these conditions before adding another

• The installation must remain suitable for multiple fish at the 90 cm adult planning size.
• Every fish must have reliable access to food without one individual dominating each feeding period.
• The cover, filtration, oxygenation and weekly maintenance routine must work for the combined stocking load.
• A practical separation plan must be ready if the hierarchy produces persistent aggression or prevents normal feeding.

Watch behaviour, not just injuries

Keeping a single fish avoids the aggression that limited space can trigger between these arowanas and the pecking order a group forms. It does not make mixed stocking automatic: any other animal must still pass the swallowing, aggression, surface-competition and filtration tests.

Answer the key buyer questions

How big does a Silver Albino Arowana get?

It reaches a recorded maximum of 90 cm total length according to FishBase. Plan the permanent installation around that 90 cm figure.

What size aquarium does a Silver Albino Arowana need?

Seriously Fish limits it to public installations or the very largest private aquaria. OATA says tankbusters require an exceptionally large aquarium, often in excess of 500 litres, but plan this 90 cm surface fish around the stricter species requirement, a heavy cover and adult-scale filtration.

How many should I keep together?

Plan for one fish unless a very large installation has been assessed for several adults. It may be aggressive towards its own kind when space is limited, and groups form a pecking order even in larger systems.

Is a Silver Albino Arowana suitable for beginners?

No. This is an advanced fish requiring a public installation or one of the very largest private aquaria, a heavy tightly fitting cover, mature filtration, stable water and weekly 30–50% water changes.

What does this fish eat?

Feed varied bloodworm, earthworms, prawn, shrimp, mussels, suitable fish flesh and insects, with floating dried foods used only in limited quantities. OATA’s tankbuster guidance says to feed once daily and only what is eaten within a few minutes.

What temperature and pH does a Silver Albino Arowana need?

Keep it at 24–30°C, pH 5.0–7.5 and 2–15 dGH. The temperature is the overlap between FishBase’s recorded environment and Seriously Fish’s aquarium range; the pH and hardness come from Seriously Fish.

Is it aggressive or likely to nip fins?

It is described as peaceful with fish too large to swallow, but it may attack its own kind when space is limited. Avoid aggressive competitors, watch for fin damage or changed behaviour, and separate fish that become incompatible.

Which kinds of animals can live with it?

Seriously Fish names similarly sized Cichla species and larger doradid or loricariid catfishes as the best choices, in an installation that already suits a 90 cm arowana. Avoid small fish, aggressive competitors and other surface dwellers except in the very largest systems; treat aquatic invertebrates as prey risk.

How does a Silver Albino Arowana arrive alive in the UK?

For every delivery, start filming a short continuous unboxing video before the parcel is opened, showing it still sealed, the opening and the fish still inside the sealed bag. The fish travels hand-bagged in pure oxygen in an insulated poly box, with a heat pack when the weather calls for one, carried by a licensed live-animal courier to someone present to receive it. After filming, float the bag for 20–30 minutes before releasing the fish, and never pour the bag water into the aquarium.

Check the care and identity references

• FishBase: Osteoglossum bicirrhosum — identity, family, South American distribution, environmental temperature, maximum total length and wild feeding biology.
• Seriously Fish: Osteoglossum bicirrhosum — aquarium water values, adult standard length, installation suitability, maintenance, feeding and compatibility.
• OATA: How to look after very large fish — broad tankbuster guidance for filtration, waste values, feeding, introduction and routine maintenance.
• RSPCA aquarium environment guidance — the role of established biological filtration in processing fish waste.
• Tropical Fish Co delivery policy — packing, receipt, acclimatisation and Live Arrival Guarantee conditions.