Can Neolamprologus Fasciatus and Pacific Blue Eye Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Neolamprologus Fasciatus and Pacific Blue Eye are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Neolamprologus Fasciatus

Neolamprologus fasciatus

Pacific Blue Eye

Pseudomugil signifer

🐠Family Group
Neolamprologus Fasciatus
Cichlids - African
Pacific Blue Eye
Rainbowfish
Temperament
Neolamprologus Fasciatus
Semi-Aggressive (6/10)
Pacific Blue Eye
Peaceful (2/10)
Temperature
✓ Compatible
Neolamprologus Fasciatus
24–27°C
Pacific Blue Eye
20–26°C
pH Range
✓ Compatible
Neolamprologus Fasciatus
7.8–9
Pacific Blue Eye
6.5–8
Hardness (dGH)
✓ Compatible
Neolamprologus Fasciatus
10–25
Pacific Blue Eye
5–15
Water Type
✓ Compatible
Neolamprologus Fasciatus
Freshwater Only
Pacific Blue Eye
Brackish Tolerant
Flow Preference
✓ Compatible
Neolamprologus Fasciatus
Moderate
Pacific Blue Eye
Moderate
Min Tank Volume
Combined: 200 L
Neolamprologus Fasciatus
200 L
Pacific Blue Eye
60 L
Swimming Level
Shared: 1 zone
Neolamprologus Fasciatus
BottomMiddle
Pacific Blue Eye
TopMiddle
🏷️Behavior Tags
Neolamprologus Fasciatus
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorTerritorial (Defends specific area)Aggressive to same species/look-alikes
Pacific Blue Eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Stocking calculator

Can your tank handle Neolamprologus Fasciatus and Pacific Blue Eye?

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.

Neolamprologus Fasciatus
Pacific Blue Eye
Test both in my tank

Behaviour & Temperament

Neolamprologus Fasciatus is a moderately assertive species (6/10), while Pacific Blue Eye is peaceful (2/10). This notable difference means Neolamprologus Fasciatus may occasionally assert dominance over Pacific Blue Eye.

Neolamprologus Fasciatus and Pacific 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.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Pacific Blue Eye 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 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.8 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 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Neolamprologus Fasciatus and Pacific Blue Eye together, plan for an aquarium of at least 200 litres with a minimum length of 120 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), Shells (Breeding/Hiding), Plants - Densely covered. 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

Neolamprologus Fasciatus and Pacific Blue Eye 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 Neolamprologus Fasciatus and Pacific Blue Eye.

Show 5 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Neolamprologus Fasciatus is a known shrimp eater and may prey on small invertebrates or nano fish like Pacific Blue Eye.

Frequently Asked Questions

Can Neolamprologus Fasciatus and Pacific Blue Eye live together?

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

What size tank do Neolamprologus Fasciatus and Pacific Blue Eye need?

A minimum of 200 litres (tank length at least 120 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 Neolamprologus Fasciatus and Pacific Blue Eye together?

Keep the aquarium between 24°C and 26°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Neolamprologus Fasciatus or Pacific Blue Eye aggressive?

Neolamprologus Fasciatus is moderately assertive (6/10) and Pacific 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 Neolamprologus Fasciatus and Pacific Blue Eye need?

Both species overlap in the 7.8–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Neolamprologus Fasciatus's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Neolamprologus Fasciatus 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 7, 2026
Last updated
May 7, 2026
Issues or corrections?
Contact the editorial team

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