Can Convict Cichlid and Forktail Blue-eye Live Together?

🟡Possible with Caution

Keeping Convict Cichlid and Forktail Blue-eye together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 90 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Convict Cichlid

Amatitlania nigrofasciata

Forktail Blue-eye

Pseudomugil furcatus

🐠Family Group
Convict Cichlid
Cichlids - Central American
Forktail Blue-eye
Rainbowfish
Temperament
Convict Cichlid
Aggressive (8/10)
Forktail Blue-eye
Peaceful (2/10)
Temperature
✓ Compatible
Convict Cichlid
22–28°C
Forktail Blue-eye
24–28°C
pH Range
✓ Compatible
Convict Cichlid
6.5–8
Forktail Blue-eye
7–8
Hardness (dGH)
✓ Compatible
Convict Cichlid
6–20
Forktail Blue-eye
5–15
Water Type
✓ Compatible
Convict Cichlid
Freshwater Only
Forktail Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Convict Cichlid
Moderate
Forktail Blue-eye
Moderate
Min Tank Volume
Combined: 90 L
Convict Cichlid
75 L
Forktail Blue-eye
55 L
Swimming Level
Shared: 1 zone
Convict Cichlid
MiddleBottom
Forktail Blue-eye
TopMiddle
🏷️Behavior Tags
Convict Cichlid
Digger (Disturbs Substrate)Generally AggressiveFin NipperTerritorial (Defends specific area)Plant Destroyer
Forktail Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)

Behaviour & Temperament

Convict Cichlid is a semi-aggressive species (8/10), while Forktail Blue-eye is peaceful (2/10). This notable difference means Convict Cichlid may occasionally assert dominance over Forktail Blue-eye.

Large aggression gap (6 points) between Convict Cichlid and Forktail Blue-eye increases stress risk for the more peaceful fish.

Convict Cichlid and Forktail Blue-eye 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.

Worth noting: Forktail Blue-eye 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 Convict Cichlid and Forktail Blue-eye 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 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 6–15 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Convict Cichlid and Forktail Blue-eye together, plan for an aquarium of at least 90 litres with a minimum length of 75 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: Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Convict Cichlid is a plant destroyer, which conflicts with Forktail Blue-eye's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Convict Cichlid and Forktail Blue-eye live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 90 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Convict Cichlid and Forktail Blue-eye need?

A minimum of 90 litres (tank length at least 75 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 Convict Cichlid and Forktail Blue-eye 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 Convict Cichlid or Forktail Blue-eye aggressive?

Convict Cichlid is semi-aggressive (8/10) and Forktail Blue-eye is peaceful (2/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Convict Cichlid and Forktail Blue-eye need?

Both species overlap in the 7–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Convict Cichlid nip Forktail Blue-eye's fins?

Convict Cichlid is a known fin nipper. If Forktail Blue-eye has long or flowing fins, there is a real risk of fin damage. Keeping Convict Cichlid in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Convict Cichlid's territorial behaviour?

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


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