Can Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra Live Together?

Not Recommended

Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra are not recommended as tank mates due to conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Blue Dolphin (Hap)

Cyrtocara moorii

Brilliant Rummy-Nose Tetra

Hemigrammus bleheri

🐠Family Group
Blue Dolphin (Hap)
Cichlids - African
Brilliant Rummy-Nose Tetra
Characins
Temperament
Blue Dolphin (Hap)
Semi-Aggressive (5/10)
Brilliant Rummy-Nose Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Blue Dolphin (Hap)
24–28°C
Brilliant Rummy-Nose Tetra
24–28°C
pH Range
✗ No overlap
Blue Dolphin (Hap)
7.5–8.6
Brilliant Rummy-Nose Tetra
5–7
Hardness (dGH)
✗ No overlap
Blue Dolphin (Hap)
10–25
Brilliant Rummy-Nose Tetra
1–8
Water Type
✓ Compatible
Blue Dolphin (Hap)
Freshwater Only
Brilliant Rummy-Nose Tetra
Freshwater Only
Flow Preference
✓ Compatible
Blue Dolphin (Hap)
Moderate
Brilliant Rummy-Nose Tetra
Moderate
Min Tank Volume
Combined: 475 L
Blue Dolphin (Hap)
475 L
Brilliant Rummy-Nose Tetra
75 L
Swimming Level
Shared: 2 zones
Blue Dolphin (Hap)
MiddleBottom
Brilliant Rummy-Nose Tetra
MiddleBottom
🏷️Behavior Tags
Blue Dolphin (Hap)
Digger (Disturbs Substrate)Hyperactive / Fast SwimmerAggressive to same species/look-alikes
Brilliant Rummy-Nose Tetra
Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra?

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.

Blue Dolphin (Hap)
Brilliant Rummy-Nose Tetra
Test both in my tank

Behaviour & Temperament

Blue Dolphin (Hap) is a moderately assertive species (5/10), while Brilliant Rummy-Nose Tetra is peaceful (1/10). This notable difference means Blue Dolphin (Hap) may occasionally assert dominance over Brilliant Rummy-Nose Tetra.

Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

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 Blue Dolphin (Hap) (7.5–8.6) and Brilliant Rummy-Nose Tetra (5–7) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Blue Dolphin (Hap) needs 10–25 dGH while Brilliant Rummy-Nose Tetra requires 1–8 dGH.

Tank Setup

To house Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra together, plan for an aquarium of at least 475 litres with a minimum length of 150 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), Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Leaf Litter/Blackwater. 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra.

Frequently Asked Questions

Can Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra live together?

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

What size tank do Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra need?

A minimum of 475 litres (tank length at least 150 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 Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra 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 Blue Dolphin (Hap) or Brilliant Rummy-Nose Tetra aggressive?

Blue Dolphin (Hap) is moderately assertive (5/10) and Brilliant Rummy-Nose Tetra is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Blue Dolphin (Hap) and Brilliant Rummy-Nose Tetra need?

Their pH requirements do not overlap. Blue Dolphin (Hap) prefers 7.5–8.6, while Brilliant Rummy-Nose Tetra needs 5–7. This makes them incompatible in the same water chemistry.


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