Can Freshwater Angelfish and Gertrude's Spotted Blue-eye Live Together?

Reviewed by Guidarium Editorial DeskUpdated April 28, 2026
Not Recommended

Freshwater Angelfish and Gertrude's Spotted 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

Freshwater Angelfish

Pterophyllum scalare

Gertrude's Spotted Blue-eye

Pseudomugil gertrudae

🐠Family Group
Freshwater Angelfish
Cichlids - South American
Gertrude's Spotted Blue-eye
Rainbowfish
Temperament
Freshwater Angelfish
Semi-Aggressive (6/10)
Gertrude's Spotted Blue-eye
Peaceful (2/10)
Temperature
✓ Compatible
Freshwater Angelfish
24–30°C
Gertrude's Spotted Blue-eye
21–28°C
pH Range
✓ Compatible
Freshwater Angelfish
6–7.8
Gertrude's Spotted Blue-eye
6–7.5
Hardness (dGH)
✓ Compatible
Freshwater Angelfish
3–15
Gertrude's Spotted Blue-eye
5–15
Water Type
✓ Compatible
Freshwater Angelfish
Freshwater Only
Gertrude's Spotted Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Freshwater Angelfish
Low
Gertrude's Spotted Blue-eye
Moderate
Min Tank Volume
Combined: 150 L
Freshwater Angelfish
150 L
Gertrude's Spotted Blue-eye
38 L
Swimming Level
Shared: 2 zones
Freshwater Angelfish
MiddleTop
Gertrude's Spotted Blue-eye
TopMiddle
🏷️Behavior Tags
Freshwater Angelfish
Piscivore (Eats small/nano fish)Shrimp EaterAggressive to same species/look-alikesTerritorial (Defends specific area)Fin Nipper
Gertrude's Spotted Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Stocking calculator

Can your tank handle Freshwater Angelfish and Gertrude's Spotted 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.

Freshwater Angelfish
Gertrude's Spotted Blue-eye
Test both in my tank

Behaviour & Temperament

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

Freshwater Angelfish and Gertrude's Spotted Blue-eye both frequent the Middle (Open Water) and Top (Surface) 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: 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.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Freshwater Angelfish and Gertrude's Spotted Blue-eye together, plan for an aquarium of at least 150 litres with a minimum length of 90 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, Driftwood (Digestion/Hiding), Plants - lighly covered, Plants - Floating, Leaf Litter/Blackwater. 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 Usually Fails in Practice

Freshwater Angelfish and Gertrude's Spotted 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 Freshwater Angelfish and Gertrude's Spotted Blue-eye.

Show 9 more tank sizes

Diet & Feeding

Feeding time deserves special attention with this pairing. Freshwater Angelfish is a known shrimp eater and may prey on small invertebrates or nano fish like Gertrude's Spotted Blue-eye.

Frequently Asked Questions

Can Freshwater Angelfish and Gertrude's Spotted Blue-eye live together?

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

What size tank do Freshwater Angelfish and Gertrude's Spotted Blue-eye need?

A minimum of 150 litres (tank length at least 90 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 Freshwater Angelfish and Gertrude's Spotted 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 Freshwater Angelfish or Gertrude's Spotted Blue-eye aggressive?

Freshwater Angelfish is moderately assertive (6/10) and Gertrude's Spotted 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 Freshwater Angelfish and Gertrude's Spotted Blue-eye need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Freshwater Angelfish nip Gertrude's Spotted Blue-eye's fins?

Freshwater Angelfish is a known fin nipper. If Gertrude's Spotted Blue-eye has long or flowing fins, there is a real risk of fin damage. Keeping Freshwater Angelfish in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Freshwater Angelfish's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Freshwater Angelfish 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
April 28, 2026
Last updated
April 28, 2026
Issues or corrections?
Contact the editorial team

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