Can Black Pacu and Silver Arowana Live Together?

🟡Possible with Caution

Keeping Black Pacu and Silver Arowana together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 4560 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Black Pacu

Colossoma macropomum

Silver Arowana

Osteoglossum bicirrhosum

🐠Family Group
Black Pacu
Characins
Silver Arowana
Oddballs
Temperament
Black Pacu
Mostly Peaceful (4/10)
Silver Arowana
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Black Pacu
22–28°C
Silver Arowana
24–30°C
pH Range
✓ Compatible
Black Pacu
6–7.5
Silver Arowana
6–7.5
Hardness (dGH)
✓ Compatible
Black Pacu
2–15
Silver Arowana
1–12
Water Type
✓ Compatible
Black Pacu
Freshwater Only
Silver Arowana
Freshwater Only
Flow Preference
✓ Compatible
Black Pacu
Moderate
Silver Arowana
Moderate
Min Tank Volume
Combined: 4560 L
Black Pacu
3800 L
Silver Arowana
1000 L
Swimming Level
✓ Different zones
Black Pacu
MiddleBottom
Silver Arowana
Top
🏷️Behavior Tags
Black Pacu
Plant DestroyerHyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)Fry Predator
Silver Arowana
Piscivore (Eats small/nano fish)Jumper (Lid Required)Hyperactive / Fast SwimmerGenerally AggressiveTerritorial (Defends specific area)

Behaviour & Temperament

Black Pacu is a generally mild-mannered species (4/10), while Silver Arowana is moderately assertive (6/10). This modest difference means Silver Arowana may occasionally assert dominance over Black Pacu.

In terms of spatial distribution, Black Pacu prefers the Middle (Open Water) and Bottom (Substrate) zones, whereas Silver Arowana occupies the Top (Surface) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Black Pacu is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Black Pacu and Silver Arowana to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Black Pacu and Silver Arowana together, plan for an aquarium of at least 4560 litres with a minimum length of 300 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

Frequently Asked Questions

Can Black Pacu and Silver Arowana live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 4560 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Black Pacu and Silver Arowana need?

A minimum of 4560 litres (tank length at least 300 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Black Pacu and Silver Arowana together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Black Pacu or Silver Arowana aggressive?

Black Pacu is generally mild-mannered (4/10) and Silver Arowana is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Black Pacu and Silver Arowana need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Silver Arowana's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Silver Arowana space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.


Related Comparisons