Can Congo Tetra and Head and Tail Light Tetra Live Together?

Possible with Caution

Keeping Congo Tetra and Head and Tail Light Tetra together is possible but requires caution due to potential behavioral clashes. 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

Congo Tetra

Phenacogrammus interruptus

Head and Tail Light Tetra

Hemigrammus ocellifer

🐟Family Group
Congo Tetra
Characins
Head and Tail Light Tetra
Characins
Temperament
Congo Tetra
Peaceful (2/10)
Head and Tail Light Tetra
Peaceful (1/10)
Temperature
✓ Compatible
Congo Tetra
23–28°C
Head and Tail Light Tetra
24–28°C
pH Range
✓ Compatible
Congo Tetra
6–7.5
Head and Tail Light Tetra
6–7.5
Hardness (dGH)
✓ Compatible
Congo Tetra
3–18
Head and Tail Light Tetra
4–15
Water Type
✓ Compatible
Congo Tetra
Freshwater Only
Head and Tail Light Tetra
Freshwater Only
Flow Preference
✓ Compatible
Congo Tetra
Moderate
Head and Tail Light Tetra
Moderate
Min Tank Volume
Combined: 110 L
Congo Tetra
110 L
Head and Tail Light Tetra
60 L
Swimming Level
Shared: 2 zones
Congo Tetra
MiddleTop
Head and Tail Light Tetra
MiddleTop
🏷️Behavior Tags
Congo Tetra
Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)Jumper (Lid Required)Fry Predator
Head and Tail Light Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Congo Tetra and Head and Tail Light 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.

Congo Tetra
Head and Tail Light Tetra
Test both in my tank

Behaviour & Temperament

Congo Tetra is a peaceful species (2/10), while Head and Tail Light Tetra is peaceful (1/10). This modest difference means Congo Tetra may occasionally assert dominance over Head and Tail Light Tetra.

Congo Tetra and Head and Tail Light Tetra both frequent the Middle (Open Water) and Top (Surface) 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: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Congo Tetra 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.

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 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 4–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Congo Tetra and Head and Tail Light 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 — 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, Plants - Floating, 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 Congo Tetra and Head and Tail Light Tetra.

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Frequently Asked Questions

Can Congo Tetra and Head and Tail Light 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 Congo Tetra and Head and Tail Light 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 Congo Tetra and Head and Tail Light 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 Congo Tetra or Head and Tail Light Tetra aggressive?

Congo Tetra is peaceful (2/10) and Head and Tail Light Tetra is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Congo Tetra and Head and Tail Light Tetra need?

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


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