Can Dwarf Neon Rainbowfish (Praecox) and Severum Live Together?

🟢Ideal Tank Mates

Yes, Dwarf Neon Rainbowfish (Praecox) and Severum are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 336 litres is recommended.


At a Glance

Dwarf Neon Rainbowfish (Praecox)

Melanotaenia praecox

Severum

Heros severus

🐠Family Group
Dwarf Neon Rainbowfish (Praecox)
Rainbowfish
Severum
Cichlids - South American
Temperament
Dwarf Neon Rainbowfish (Praecox)
Peaceful (2/10)
Severum
Semi-Aggressive (5/10)
Temperature
✓ Compatible
Dwarf Neon Rainbowfish (Praecox)
23–28°C
Severum
24–29°C
pH Range
✓ Compatible
Dwarf Neon Rainbowfish (Praecox)
6.5–8
Severum
6–7.5
Hardness (dGH)
✓ Compatible
Dwarf Neon Rainbowfish (Praecox)
5–15
Severum
4–15
Water Type
✓ Compatible
Dwarf Neon Rainbowfish (Praecox)
Freshwater Only
Severum
Freshwater Only
Flow Preference
✓ Compatible
Dwarf Neon Rainbowfish (Praecox)
Moderate
Severum
Moderate
Min Tank Volume
Combined: 336 L
Dwarf Neon Rainbowfish (Praecox)
75 L
Severum
280 L
Swimming Level
Shared: 1 zone
Dwarf Neon Rainbowfish (Praecox)
TopMiddle
Severum
MiddleBottom
🏷️Behavior Tags
Dwarf Neon Rainbowfish (Praecox)
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)
Severum
Plant DestroyerTerritorial (Defends specific area)Digger (Disturbs Substrate)

Behaviour & Temperament

Dwarf Neon Rainbowfish (Praecox) is a peaceful species (2/10), while Severum is moderately assertive (5/10). This modest difference means Severum may occasionally assert dominance over Dwarf Neon Rainbowfish (Praecox).

Dwarf Neon Rainbowfish (Praecox) and Severum 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: Dwarf Neon Rainbowfish (Praecox) 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 6.5 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. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Dwarf Neon Rainbowfish (Praecox) and Severum together, plan for an aquarium of at least 336 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Severum is a plant destroyer, which conflicts with Dwarf Neon Rainbowfish (Praecox)'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.

Find the right tank equipment

Browse tanks, décor, and equipment suited for this setup.

Frequently Asked Questions

Can Dwarf Neon Rainbowfish (Praecox) and Severum live together?

Yes. Dwarf Neon Rainbowfish (Praecox) and Severum are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Dwarf Neon Rainbowfish (Praecox) and Severum need?

A minimum of 336 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 Dwarf Neon Rainbowfish (Praecox) and Severum 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 Dwarf Neon Rainbowfish (Praecox) or Severum aggressive?

Dwarf Neon Rainbowfish (Praecox) is peaceful (2/10) and Severum is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Dwarf Neon Rainbowfish (Praecox) and Severum need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

How do I manage Severum's territorial behaviour?

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


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