Can Pink Tailed Chalceus and Weeksi Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Pink Tailed Chalceus and Weeksi Bichir together is possible but requires caution due to mismatched flow preferences. Provide a spacious tank of at least 470 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Pink Tailed Chalceus

Chalceus macrolepidotus

Weeksi Bichir

Polypterus weeksii

🐠Family Group
Pink Tailed Chalceus
Characins
Weeksi Bichir
Oddballs
Temperament
Pink Tailed Chalceus
Semi-Aggressive (6/10)
Weeksi Bichir
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Pink Tailed Chalceus
23–28°C
Weeksi Bichir
24–28°C
pH Range
✓ Compatible
Pink Tailed Chalceus
6–7.5
Weeksi Bichir
6–7.5
Hardness (dGH)
✓ Compatible
Pink Tailed Chalceus
5–15
Weeksi Bichir
5–15
Water Type
✓ Compatible
Pink Tailed Chalceus
Freshwater Only
Weeksi Bichir
Freshwater Only
Flow Preference
✗ No overlap
Pink Tailed Chalceus
High
Weeksi Bichir
Low
Min Tank Volume
Combined: 470 L
Pink Tailed Chalceus
250 L
Weeksi Bichir
470 L
Swimming Level
✓ Different zones
Pink Tailed Chalceus
Top
Weeksi Bichir
Bottom
🏷️Behavior Tags
Pink Tailed Chalceus
Jumper (Lid Required)Piscivore (Eats small/nano fish)Hyperactive / Fast SwimmerShrimp EaterAggressive to same species/look-alikes
Weeksi Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Pink Tailed Chalceus 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.

Pink Tailed Chalceus
Weeksi Bichir
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Behaviour & Temperament

Both Pink Tailed Chalceus and Weeksi Bichir are moderately assertive species with an aggression score of 6/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

In terms of spatial distribution, Pink Tailed Chalceus prefers the Top (Surface) zone, whereas Weeksi Bichir occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Weeksi Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Pink Tailed Chalceus 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 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Pink Tailed Chalceus and Weeksi Bichir together, plan for an aquarium of at least 470 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.

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: Driftwood (Digestion/Hiding), Plants - Floating, Sand (Sifters), Smooth Gravel (Sensitive Barbels), Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

Pink Tailed Chalceus 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 Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Pink Tailed Chalceus and Weeksi Bichir need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Pink Tailed Chalceus and Weeksi Bichir.

Frequently Asked Questions

Can Pink Tailed Chalceus and Weeksi Bichir live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 470 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Pink Tailed Chalceus and Weeksi Bichir need?

A minimum of 470 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 Pink Tailed Chalceus 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 Pink Tailed Chalceus or Weeksi Bichir aggressive?

Pink Tailed Chalceus is moderately assertive (6/10) and Weeksi Bichir is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Pink Tailed Chalceus and Weeksi Bichir 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.

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
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