Can Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid 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

Gertrude's Spotted Blue-eye

Pseudomugil gertrudae

Taiwan Reef Cichlid

Protomelas sp. "Steveni Taiwan"

🐠Family Group
Gertrude's Spotted Blue-eye
Rainbowfish
Taiwan Reef Cichlid
Cichlids - African
Temperament
Gertrude's Spotted Blue-eye
Peaceful (2/10)
Taiwan Reef Cichlid
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Gertrude's Spotted Blue-eye
21–28°C
Taiwan Reef Cichlid
24–28°C
pH Range
✗ No overlap
Gertrude's Spotted Blue-eye
6–7.5
Taiwan Reef Cichlid
7.8–8.6
Hardness (dGH)
✓ Compatible
Gertrude's Spotted Blue-eye
5–15
Taiwan Reef Cichlid
10–20
Water Type
✓ Compatible
Gertrude's Spotted Blue-eye
Freshwater Only
Taiwan Reef Cichlid
Freshwater Only
Flow Preference
✓ Compatible
Gertrude's Spotted Blue-eye
Moderate
Taiwan Reef Cichlid
Moderate
Min Tank Volume
Combined: 280 L
Gertrude's Spotted Blue-eye
38 L
Taiwan Reef Cichlid
280 L
Swimming Level
Shared: 1 zone
Gertrude's Spotted Blue-eye
TopMiddle
Taiwan Reef Cichlid
MiddleBottom
🏷️Behavior Tags
Gertrude's Spotted Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Taiwan Reef Cichlid
Territorial (Defends specific area)Aggressive to same species/look-alikesHyperactive / Fast SwimmerDigger (Disturbs Substrate)Plant DestroyerFry Predator
Stocking calculator

Can your tank handle Gertrude's Spotted Blue-eye and Taiwan Reef 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.

Gertrude's Spotted Blue-eye
Taiwan Reef Cichlid
Test both in my tank

Behaviour & Temperament

Gertrude's Spotted Blue-eye is a peaceful species (2/10), while Taiwan Reef Cichlid is moderately assertive (6/10). This notable difference means Taiwan Reef Cichlid may occasionally assert dominance over Gertrude's Spotted Blue-eye.

Gertrude's Spotted Blue-eye and Taiwan Reef 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.

Worth noting: Gertrude's Spotted 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Gertrude's Spotted Blue-eye (6–7.5) and Taiwan Reef Cichlid (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid together, plan for an aquarium of at least 280 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: Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Taiwan Reef Cichlid is a plant destroyer, which conflicts with Gertrude's Spotted 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.

Why This Pairing Usually Fails in Practice

Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid 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 Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid.

Show 1 more tank size

Frequently Asked Questions

Can Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid live together?

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

What size tank do Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid need?

A minimum of 280 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 Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid 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 Gertrude's Spotted Blue-eye or Taiwan Reef Cichlid aggressive?

Gertrude's Spotted Blue-eye is peaceful (2/10) and Taiwan Reef 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 Gertrude's Spotted Blue-eye and Taiwan Reef Cichlid need?

Their pH requirements do not overlap. Gertrude's Spotted Blue-eye prefers 6–7.5, while Taiwan Reef Cichlid needs 7.8–8.6. This makes them incompatible in the same water chemistry.

How do I manage Taiwan Reef Cichlid's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Taiwan Reef 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 11, 2026
Last updated
May 11, 2026
Issues or corrections?
Contact the editorial team

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