Can Dusky Millions Fish and Featherfin Cichlid Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Possible with Caution

Keeping Dusky Millions Fish and Featherfin Cichlid together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 676 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Dusky Millions Fish

Phalloceros caudimaculatus

Featherfin Cichlid

Cyathopharynx furcifer

🐠Family Group
Dusky Millions Fish
Livebearers
Featherfin Cichlid
Cichlids - African
Temperament
Dusky Millions Fish
Peaceful (2/10)
Featherfin Cichlid
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Dusky Millions Fish
16–24°C
Featherfin Cichlid
24–27°C
pH Range
✓ Compatible
Dusky Millions Fish
7–8
Featherfin Cichlid
8–9.2
Hardness (dGH)
✓ Compatible
Dusky Millions Fish
8–20
Featherfin Cichlid
10–25
Water Type
✓ Compatible
Dusky Millions Fish
Brackish Tolerant
Featherfin Cichlid
Freshwater Only
Flow Preference
✓ Compatible
Dusky Millions Fish
Low
Featherfin Cichlid
Moderate
Min Tank Volume
Combined: 676 L
Dusky Millions Fish
40 L
Featherfin Cichlid
550 L
Swimming Level
Shared: 1 zone
Dusky Millions Fish
TopMiddle
Featherfin Cichlid
MiddleBottom
🏷️Behavior Tags
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Featherfin Cichlid
Digger (Disturbs Substrate)Territorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Dusky Millions Fish and Featherfin Cichlid?

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.

Dusky Millions Fish
Featherfin Cichlid
Test both in my tank

Behaviour & Temperament

Dusky Millions Fish is a peaceful species (2/10), while Featherfin Cichlid is moderately assertive (6/10). This notable difference means Featherfin Cichlid may occasionally assert dominance over Dusky Millions Fish.

Dusky Millions Fish and Featherfin Cichlid both frequent the Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

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 Dusky Millions Fish and Featherfin Cichlid to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 24°C and 24°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 8 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Dusky Millions Fish and Featherfin Cichlid together, plan for an aquarium of at least 676 litres with a minimum length of 180 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: Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus), Sand (Sifters). Meeting these requirements will help both species thrive.

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

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. Dusky Millions Fish and Featherfin Cichlid 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 Dusky Millions Fish and Featherfin Cichlid.

Frequently Asked Questions

Can Dusky Millions Fish and Featherfin Cichlid live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 676 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Dusky Millions Fish and Featherfin Cichlid need?

A minimum of 676 litres (tank length at least 180 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 Dusky Millions Fish and Featherfin Cichlid together?

Keep the aquarium between 24°C and 24°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Dusky Millions Fish or Featherfin Cichlid aggressive?

Dusky Millions Fish is peaceful (2/10) and Featherfin Cichlid is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Dusky Millions Fish and Featherfin Cichlid need?

Both species overlap in the 8–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Featherfin Cichlid's fins?

Dusky Millions Fish is a known fin nipper. If Featherfin Cichlid has long or flowing fins, there is a real risk of fin damage. Keeping Dusky Millions Fish in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Featherfin Cichlid's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Featherfin Cichlid 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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

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