Can Betta Smaragdina and Congo Tetra Live Together?

Possible with Caution

Keeping Betta Smaragdina and Congo Tetra together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 110 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Betta Smaragdina

Betta smaragdina

Congo Tetra

Phenacogrammus interruptus

🐠Family Group
Betta Smaragdina
Anabantoids
Congo Tetra
Characins
Temperament
Betta Smaragdina
Semi-Aggressive (5/10)
Congo Tetra
Peaceful (2/10)
Temperature
βœ“ Compatible
Betta Smaragdina
22–28Β°C
Congo Tetra
23–28Β°C
pH Range
βœ“ Compatible
Betta Smaragdina
5.5–7.5
Congo Tetra
6–7.5
Hardness (dGH)
βœ“ Compatible
Betta Smaragdina
2–12
Congo Tetra
3–18
Water Type
βœ“ Compatible
Betta Smaragdina
Freshwater Only
Congo Tetra
Freshwater Only
Flow Preference
βœ“ Compatible
Betta Smaragdina
Low
Congo Tetra
Moderate
Min Tank Volume
Combined: 110 L
Betta Smaragdina
20 L
Congo Tetra
110 L
Swimming Level
Shared: 2 zones
Betta Smaragdina
TopMiddle
Congo Tetra
MiddleTop
🏷️Behavior Tags
Betta Smaragdina
Shrimp EaterFry PredatorJumper (Lid Required)Territorial (Defends specific area)Aggressive to same species/look-alikes
Congo Tetra
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Fry Predator
Stocking calculator

Can your tank handle Betta Smaragdina and Congo 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.

Betta Smaragdina
Congo Tetra
Test both in my tank

Behaviour & Temperament

Betta Smaragdina is a moderately assertive species (5/10), while Congo Tetra is peaceful (2/10). This modest difference means Betta Smaragdina may occasionally assert dominance over Congo Tetra.

Betta Smaragdina and Congo Tetra both frequent the Top (Surface) and 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: Betta Smaragdina is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Betta Smaragdina and Congo Tetra to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

Water Parameters

The safe temperature window for both species falls between 23Β°C and 28Β°C. Aim for the midpoint of this range (around 25.5Β°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 3–12 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Betta Smaragdina and Congo Tetra together, plan for an aquarium of at least 110 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 β€” caves, driftwood, and dense plant clusters β€” so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Betta Smaragdina and Congo Tetra.

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Frequently Asked Questions

Can Betta Smaragdina and Congo Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 110 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Betta Smaragdina and Congo Tetra need?

A minimum of 110 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 Betta Smaragdina and Congo Tetra together?

Keep the aquarium between 23Β°C and 28Β°C. A target of around 25.5Β°C sits comfortably within both species' preferred ranges.

Are Betta Smaragdina or Congo Tetra aggressive?

Betta Smaragdina is moderately assertive (5/10) and Congo Tetra is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Betta Smaragdina and Congo Tetra need?

Both species overlap in the 6–7.5 pH range. Consistency is key β€” avoid sudden swings, and test regularly to stay within this window.

How do I manage Betta Smaragdina's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Betta Smaragdina space to claim a territory without encroaching on the other fish's area. Adding dΓ©cor that divides the tank into distinct zones works especially well.


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