Can Figure 8 Puffer (Brackish) and Rummy-Nose Tetra Live Together?

🔴Not Recommended

Figure 8 Puffer (Brackish) and Rummy-Nose Tetra are not recommended as tank mates due to incompatible water types and 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

Figure 8 Puffer (Brackish)

Dichotomyctere ocellatus

Rummy-Nose Tetra

Hemigrammus rhodostomus

🐠Family Group
Figure 8 Puffer (Brackish)
Puffers
Rummy-Nose Tetra
Characins
Temperament
Figure 8 Puffer (Brackish)
Aggressive (8/10)
Rummy-Nose Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Figure 8 Puffer (Brackish)
24–28°C
Rummy-Nose Tetra
24–28°C
pH Range
✗ No overlap
Figure 8 Puffer (Brackish)
7.5–8.5
Rummy-Nose Tetra
5.5–7
Hardness (dGH)
✓ Compatible
Figure 8 Puffer (Brackish)
10–25
Rummy-Nose Tetra
1–12
Water Type
✗ No overlap
Figure 8 Puffer (Brackish)
Brackish Required
Rummy-Nose Tetra
Freshwater Only
Flow Preference
✓ Compatible
Figure 8 Puffer (Brackish)
Moderate
Rummy-Nose Tetra
Moderate
Min Tank Volume
Combined: 90 L
Figure 8 Puffer (Brackish)
60 L
Rummy-Nose Tetra
75 L
Swimming Level
Shared: 2 zones
Figure 8 Puffer (Brackish)
MiddleBottom
Rummy-Nose Tetra
MiddleBottom
🏷️Behavior Tags
Figure 8 Puffer (Brackish)
Snail EaterShrimp EaterFin NipperGenerally AggressiveTerritorial (Defends specific area)Hyperactive / Fast Swimmer
Rummy-Nose Tetra
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Fry PredatorNano / Bite-sized (Predation Risk)

Behaviour & Temperament

Figure 8 Puffer (Brackish) is a semi-aggressive species (8/10), while Rummy-Nose Tetra is peaceful (1/10). This notable difference means Figure 8 Puffer (Brackish) may occasionally assert dominance over Rummy-Nose Tetra.

Large aggression gap (7 points) between Figure 8 Puffer (Brackish) and Rummy-Nose Tetra increases stress risk for the more peaceful fish.

Figure 8 Puffer (Brackish) and 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.

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

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 Figure 8 Puffer (Brackish) (7.5–8.5) and Rummy-Nose Tetra (5.5–7) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Figure 8 Puffer (Brackish) and Rummy-Nose Tetra together, plan for an aquarium of at least 90 litres with a minimum length of 75 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: Sand (Sifters), Shells (Breeding/Hiding), Plants - Densely covered, Plants - lighly 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.

Find the right tank equipment

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

Diet & Feeding

Feeding time deserves special attention with this pairing. Figure 8 Puffer (Brackish) is a known shrimp eater and may prey on small invertebrates or nano fish like Rummy-Nose Tetra.

Frequently Asked Questions

Can Figure 8 Puffer (Brackish) and Rummy-Nose Tetra live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Figure 8 Puffer (Brackish) and Rummy-Nose Tetra need?

A minimum of 90 litres (tank length at least 75 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 Figure 8 Puffer (Brackish) and 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 Figure 8 Puffer (Brackish) or Rummy-Nose Tetra aggressive?

Figure 8 Puffer (Brackish) is semi-aggressive (8/10) and 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 Figure 8 Puffer (Brackish) and Rummy-Nose Tetra need?

Their pH requirements do not overlap. Figure 8 Puffer (Brackish) prefers 7.5–8.5, while Rummy-Nose Tetra needs 5.5–7. This makes them incompatible in the same water chemistry.

Will Figure 8 Puffer (Brackish) nip Rummy-Nose Tetra's fins?

Figure 8 Puffer (Brackish) is a known fin nipper. If Rummy-Nose Tetra has long or flowing fins, there is a real risk of fin damage. Keeping Figure 8 Puffer (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Figure 8 Puffer (Brackish)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Figure 8 Puffer (Brackish) 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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