Can Altum Angel and Delicate Blue-Eye Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Altum Angel and Delicate 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

Altum Angel

Pterophyllum altum

Delicate Blue-Eye

Pseudomugil tenellus

🐠Family Group
Altum Angel
Cichlids - South American
Delicate Blue-Eye
Rainbowfish
Temperament
Altum Angel
Semi-Aggressive (5/10)
Delicate Blue-Eye
Peaceful (1/10)
Temperature
✓ Compatible
Altum Angel
27–32°C
Delicate Blue-Eye
25–32°C
pH Range
✓ Compatible
Altum Angel
4.5–6.5
Delicate Blue-Eye
5–7.5
Hardness (dGH)
✓ Compatible
Altum Angel
1–5
Delicate Blue-Eye
5–15
Water Type
✓ Compatible
Altum Angel
Freshwater Only
Delicate Blue-Eye
Brackish Tolerant
Flow Preference
✓ Compatible
Altum Angel
Low
Delicate Blue-Eye
Moderate
Min Tank Volume
Combined: 400 L
Altum Angel
400 L
Delicate Blue-Eye
60 L
Swimming Level
Shared: 1 zone
Altum Angel
Middle
Delicate Blue-Eye
TopMiddle
🏷️Behavior Tags
Altum Angel
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorTerritorial (Defends specific area)Shy / Slow Moving (Easily Stressed)
Delicate Blue-Eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Stocking calculator

Can your tank handle Altum Angel and Delicate 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.

Altum Angel
Delicate Blue-Eye
Test both in my tank

Behaviour & Temperament

Altum Angel is a moderately assertive species (5/10), while Delicate Blue-Eye is peaceful (1/10). This notable difference means Altum Angel may occasionally assert dominance over Delicate Blue-Eye.

Altum Angel and Delicate 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: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Worth noting: Delicate Blue-Eye is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 27°C and 32°C. Aim for the midpoint of this range (around 29.5°C) for optimal comfort.

Both fish can tolerate a pH between 5 and 6.5. Maintaining a stable value within this band is more important than hitting an exact number.

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

Tank Setup

To house Altum Angel and Delicate Blue-Eye together, plan for an aquarium of at least 400 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), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Floating, Plants - Densely covered. 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

Altum Angel and Delicate 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 Altum Angel and Delicate Blue-Eye.

Diet & Feeding

Feeding time deserves special attention with this pairing. Altum Angel is a known shrimp eater and may prey on small invertebrates or nano fish like Delicate Blue-Eye.

Frequently Asked Questions

Can Altum Angel and Delicate Blue-Eye live together?

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

What size tank do Altum Angel and Delicate Blue-Eye need?

A minimum of 400 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 Altum Angel and Delicate Blue-Eye together?

Keep the aquarium between 27°C and 32°C. A target of around 29.5°C sits comfortably within both species' preferred ranges.

Are Altum Angel or Delicate Blue-Eye aggressive?

Altum Angel is moderately assertive (5/10) and Delicate Blue-Eye is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Altum Angel and Delicate Blue-Eye need?

Both species overlap in the 5–6.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Altum Angel's territorial behaviour?

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