Can Ajamaru Rainbowfish and Buenos Aires Tetra Live Together?

Possible with Caution

Keeping Ajamaru Rainbowfish and Buenos Aires Tetra together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 150 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Ajamaru Rainbowfish

Melanotaenia ajamaruensis

Buenos Aires Tetra

Hyphessobrycon anisitsi

🐠Family Group
Ajamaru Rainbowfish
Rainbowfish
Buenos Aires Tetra
Characins
Temperament
Ajamaru Rainbowfish
Peaceful (2/10)
Buenos Aires Tetra
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Ajamaru Rainbowfish
24–28°C
Buenos Aires Tetra
16–28°C
pH Range
✓ Compatible
Ajamaru Rainbowfish
7.2–8.5
Buenos Aires Tetra
6–8
Hardness (dGH)
✓ Compatible
Ajamaru Rainbowfish
8–20
Buenos Aires Tetra
2–25
Water Type
✓ Compatible
Ajamaru Rainbowfish
Freshwater Only
Buenos Aires Tetra
Freshwater Only
Flow Preference
✓ Compatible
Ajamaru Rainbowfish
Moderate
Buenos Aires Tetra
Moderate
Min Tank Volume
Combined: 150 L
Ajamaru Rainbowfish
150 L
Buenos Aires Tetra
110 L
Swimming Level
Shared: 1 zone
Ajamaru Rainbowfish
TopMiddle
Buenos Aires Tetra
Middle
🏷️Behavior Tags
Ajamaru Rainbowfish
Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Buenos Aires Tetra
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Ajamaru Rainbowfish and Buenos Aires 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.

Ajamaru Rainbowfish
Buenos Aires Tetra
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Behaviour & Temperament

Ajamaru Rainbowfish is a peaceful species (2/10), while Buenos Aires Tetra is moderately assertive (6/10). This notable difference means Buenos Aires Tetra may occasionally assert dominance over Ajamaru Rainbowfish.

Ajamaru Rainbowfish and Buenos Aires Tetra 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: Ajamaru Rainbowfish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

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 7.2 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Ajamaru Rainbowfish and Buenos Aires Tetra 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

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: Buenos Aires Tetra is a plant destroyer, which conflicts with Ajamaru Rainbowfish'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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Ajamaru Rainbowfish and Buenos Aires Tetra.

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Frequently Asked Questions

Can Ajamaru Rainbowfish and Buenos Aires Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 150 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Ajamaru Rainbowfish and Buenos Aires Tetra 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 Ajamaru Rainbowfish and Buenos Aires 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 Ajamaru Rainbowfish or Buenos Aires Tetra aggressive?

Ajamaru Rainbowfish is peaceful (2/10) and Buenos Aires Tetra is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Ajamaru Rainbowfish and Buenos Aires Tetra need?

Both species overlap in the 7.2–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Buenos Aires Tetra nip Ajamaru Rainbowfish's fins?

Buenos Aires Tetra is a known fin nipper. If Ajamaru Rainbowfish has long or flowing fins, there is a real risk of fin damage. Keeping Buenos Aires Tetra in a larger group can help redirect nipping behaviour toward conspecifics.


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