Can Featherfin Cichlid and Threadfin Rainbowfish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Featherfin Cichlid and Threadfin Rainbowfish are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Featherfin Cichlid

Cyathopharynx furcifer

Threadfin Rainbowfish

Iriatherina werneri

🐠Family Group
Featherfin Cichlid
Cichlids - African
Threadfin Rainbowfish
Rainbowfish
Temperament
Featherfin Cichlid
Semi-Aggressive (6/10)
Threadfin Rainbowfish
Peaceful (1/10)
Temperature
✓ Compatible
Featherfin Cichlid
24–27°C
Threadfin Rainbowfish
23–29°C
pH Range
✗ No overlap
Featherfin Cichlid
8–9.2
Threadfin Rainbowfish
5.5–7.5
Hardness (dGH)
✓ Compatible
Featherfin Cichlid
10–25
Threadfin Rainbowfish
1–12
Water Type
✓ Compatible
Featherfin Cichlid
Freshwater Only
Threadfin Rainbowfish
Freshwater Only
Flow Preference
✓ Compatible
Featherfin Cichlid
Moderate
Threadfin Rainbowfish
Low
Min Tank Volume
Combined: 665 L
Featherfin Cichlid
550 L
Threadfin Rainbowfish
60 L
Swimming Level
Shared: 1 zone
Featherfin Cichlid
MiddleBottom
Threadfin Rainbowfish
TopMiddle
🏷️Behavior Tags
Featherfin Cichlid
Digger (Disturbs Substrate)Territorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast Swimmer
Threadfin Rainbowfish
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)Jumper (Lid Required)Hyperactive / Fast SwimmerAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Featherfin Cichlid and Threadfin Rainbowfish?

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.

Featherfin Cichlid
Threadfin Rainbowfish
Test both in my tank

Behaviour & Temperament

Featherfin Cichlid is a moderately assertive species (6/10), while Threadfin Rainbowfish is peaceful (1/10). This notable difference means Featherfin Cichlid may occasionally assert dominance over Threadfin Rainbowfish.

Featherfin Cichlid and Threadfin Rainbowfish 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Threadfin Rainbowfish 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 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Featherfin Cichlid (8–9.2) and Threadfin Rainbowfish (5.5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Featherfin Cichlid and Threadfin Rainbowfish together, plan for an aquarium of at least 665 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.

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), Plants - Densely covered, Plants - Floating. 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.

Why This Pairing Usually Fails in Practice

Featherfin Cichlid and Threadfin Rainbowfish 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 Featherfin Cichlid and Threadfin Rainbowfish.

Frequently Asked Questions

Can Featherfin Cichlid and Threadfin Rainbowfish live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Featherfin Cichlid and Threadfin Rainbowfish need?

A minimum of 665 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 Featherfin Cichlid and Threadfin Rainbowfish together?

Keep the aquarium between 24°C and 27°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Featherfin Cichlid or Threadfin Rainbowfish aggressive?

Featherfin Cichlid is moderately assertive (6/10) and Threadfin Rainbowfish is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Featherfin Cichlid and Threadfin Rainbowfish need?

Their pH requirements do not overlap. Featherfin Cichlid prefers 8–9.2, while Threadfin Rainbowfish needs 5.5–7.5. This makes them incompatible in the same water chemistry.

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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