Filament Tetra

Bryconaethiops microstoma

Filament Tetra is a peaceful middle-to-top swimmer. Keep in a school of at least 6.

PeacefulMiddle to top swimmerKeep in a school of at least 6Beginner – Intermediate

Save this fish or add it directly to one of your aquariums.

Need help with Filament Tetra?

Explore compatibility, care or problems using this guide and your aquarium’s conditions.

Quick facts

Adult size: ≤ 6.8" (≤ 17.2 cm)
Aquarium size: 37 US gal (140 L) or larger / ≥ 39.4" (≥ 100 cm) minimum length
Care level: Beginner – Intermediate
Temperament: Peaceful
Swimming zone: Middle to top swimmer
Temperature: 75–82°F (24–28°C)
pH: 6–7.5
GH: 8–18 dGH
Diet: Omnivore
Lifespan: up to 5 years
Group behavior: Keep in a school of at least 6

Care requirements

Care level: Beginner – Intermediate.

Lifespan: up to 5 years.

Aquarium size and space needs

Minimum aquarium size: 37 US gal (140 L) or larger / ≥ 39.4" (≥ 100 cm) minimum length. Plan the layout and stocking within that limit.

Water parameters

Suitable water: temperature 24–28 °C, pH 6–7.5, GH 8–18 dGH.

Temperament and compatibility

Filament Tetra is peaceful and suits calm community fish.

Swimming zone and behavior

This fish uses the middle to upper part of the aquarium, so leave enough open swimming space for movement and feeding.

Before adding this fish

Plan for an aquarium of 37 US gal (140 L) or larger / ≥ 39.4" (≥ 100 cm) minimum length.
Make room for its social group.
Avoid aggressive or highly competitive fish.
Keep in a school of at least 6.
Offer a varied diet suited to this species’ documented feeding habits.

Important notes

Large active schooling tetra: scientific maximum is 17.24 cm SL, while captive profiles report 12–15 cm without a size basis; care sources disagree on pH and preferred aquarium dimensions.

Similar fish profiles

Use these profiles to compare fish with similar care level, size, temperature range, or swimming behavior.

African Spottail Tetra Brachypetersius altus Same family Similar care level Same temperament Beginner – Intermediate ≤ 2.6" (≤ 6.5 cm) 75–79°F (24–26°C) African Red Eyed Tetra Arnoldichthys spilopterus Same family Similar care level Same temperament Beginner – Intermediate ≤ 3.9" (≤ 10 cm) 75–81°F (24–27°C) Blue Diamond Tetra Alestopetersius smykalai Same family Similar care level Same temperament Intermediate ≤ 2.4" (≤ 6 cm) 68–82°F (20–28°C) Blue Eyed Congo Tetra Phenacogrammus aurantiacus Same family Similar care level Same temperament Beginner – Intermediate ≤ 3.9" (≤ 10 cm) 72–79°F (22–26°C) Blue Spot African Tetra Brycinus poptae Same family Similar care level Same temperament Intermediate ≤ 7.8" (≤ 19.7 cm) 70–81°F (21–27°C) Adonis Tetra Lepidarchus adonis Same family Similar care level Same temperament Intermediate ≤ 1.2" (≤ 3 cm) 72–79°F (22–26°C)

FAQ

How large does Filament Tetra get?

Filament Tetra reaches ≤ 6.8" (≤ 17.2 cm).

What aquarium size does Filament Tetra need?

Use an aquarium of at least 37 US gal (140 L) or larger / ≥ 39.4" (≥ 100 cm) minimum length.

Is Filament Tetra peaceful?

Yes. Filament Tetra is recorded as peaceful and is best planned with calm community fish that do not harass it or dominate the feeding area.

What temperature is suitable for Filament Tetra?

Keep it between 24 to 28 °C.

Should Filament Tetra be kept alone or in a group?

Filament Tetra: Keep in a school of at least 6.