Can Scat (Brackish) and Weeksi Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Scat (Brackish) and Weeksi Bichir are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Scat (Brackish)

Scatophagus argus

Weeksi Bichir

Polypterus weeksii

🐟Family Group
Scat (Brackish)
Oddballs
Weeksi Bichir
Oddballs
Temperament
Scat (Brackish)
Mostly Peaceful (4/10)
Weeksi Bichir
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Scat (Brackish)
20–28°C
Weeksi Bichir
24–28°C
pH Range
✓ Compatible
Scat (Brackish)
7.5–8.5
Weeksi Bichir
6–7.5
Hardness (dGH)
✓ Compatible
Scat (Brackish)
12–30
Weeksi Bichir
5–15
Water Type
✗ No overlap
Scat (Brackish)
Brackish Required
Weeksi Bichir
Freshwater Only
Flow Preference
✗ No overlap
Scat (Brackish)
High
Weeksi Bichir
Low
Min Tank Volume
Combined: 505 L
Scat (Brackish)
450 L
Weeksi Bichir
470 L
Swimming Level
Shared: 1 zone
Scat (Brackish)
MiddleBottom
Weeksi Bichir
Bottom
🏷️Behavior Tags
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper
Weeksi Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Scat (Brackish) and Weeksi Bichir?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Scat (Brackish)
Weeksi Bichir
Test both in my tank

Behaviour & Temperament

Scat (Brackish) is a generally mild-mannered species (4/10), while Weeksi Bichir is moderately assertive (6/10). This modest difference means Weeksi Bichir may occasionally assert dominance over Scat (Brackish).

Scat (Brackish) and Weeksi Bichir both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Worth noting: Weeksi Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Weeksi Bichir is a known jumper, so a tight-fitting lid is essential.

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 7.5 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 12–15 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Scat (Brackish) and Weeksi Bichir together, plan for an aquarium of at least 505 litres with a minimum length of 150 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

Scat (Brackish) prefers High (River/Stream) flow while Weeksi Bichir needs Low (Still Water) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Why This Pairing Usually Fails in Practice

Scat (Brackish) and Weeksi Bichir are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Scat (Brackish) and Weeksi Bichir.

Frequently Asked Questions

Can Scat (Brackish) and Weeksi Bichir live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Scat (Brackish) and Weeksi Bichir need?

A minimum of 505 litres (tank length at least 150 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 Scat (Brackish) and Weeksi Bichir 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 Scat (Brackish) or Weeksi Bichir aggressive?

Scat (Brackish) is generally mild-mannered (4/10) and Weeksi Bichir is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Scat (Brackish) and Weeksi Bichir need?

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

Will Scat (Brackish) nip Weeksi Bichir's fins?

Scat (Brackish) is a known fin nipper. If Weeksi Bichir has long or flowing fins, there is a real risk of fin damage. Keeping Scat (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.

Does Weeksi Bichir being nocturnal affect compatibility?

Weeksi Bichir is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Weeksi Bichir during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 11, 2026
Last updated
May 11, 2026
Issues or corrections?
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