Congo Tetra

Phenacogrammus interruptus

Also sold as Congos

Synonyms Micralestes interruptus

Congo Tetra (Phenacogrammus interruptus) is a peaceful freshwater fish that reaches about 8 cm (3.1 in) and swims in open water in a shoal. It wants 73–82°F (23–28°C) and pH 6–7.5, is kept in groups of 6 or more, and needs a tank of at least 108 L (29 gal).

At a glance

Type	Fish
Adult size	8 cm (3.1 in)
Minimum tank	108 L (29 gal)
Group size	6 or more
Temperature	73–82°F (23–28°C)
pH	6–7.5
Temperament	Peaceful
Lifespan	3–5 years
Eats shrimp	Yes

Before it goes in

Congo Tetra needs at least 108 L (29 gal). The smallest size in this library that clears that is the 29 Gallon.
Keep 6 or more. Below that it hides, colours down and is far more likely to be picked on.
It eats shrimp. Cherry Shrimp, Crystal Red Shrimp and Bamboo Shrimp are on the menu.
It holds at 73–82°F (23–28°C). That shares a window with Betta and Cherry Shrimp.
A group of 6 takes up roughly 72% of what a 29 Gallon will comfortably hold, so plan the rest of the stock around it.

What tank size does it need?

At least 108 L (29 gal). The smallest size here that clears it is the 29 Gallon.

How many should I keep?

6 or more. Fewer than that and it spends its time hiding instead of out in the open.

Will it eat shrimp?

Yes. Shrimp are food to it, so pick one or the other.

What water does it want?

73–82°F (23–28°C), pH 6–7.5.

How long does it live?

3–5 years in a tank that suits it. That is how long you are signing up for.

Good tank mates

Tank mates from this library that share its temperature window, are peaceful and eat neither it nor its young: Goldfish, Bristlenose Pleco, Celestial Pearl Danio, Molly and Otocinclus.
Plants that hold up with it: Hygrophila corymbosa 'Siamensis', Water Sprite, Anubias nana 'Petite' and Cryptocoryne wendtii.

Often compared with

	Congo Tetra	Black Skirt Tetra	Bleeding Heart Tetra
Adult size	8 cm	6 cm	6 cm
Min tank	108 L	68 L	81 L
Group	6+	12+	8+
Temperature	73–82°F (23–28°C)	68–79°F (20–26°C)	70–82°F (21–28°C)
Eats shrimp	Yes	Yes	—

More livestock

Plan a tank with Congo Tetra →

Sources (6) · checked Sep 2026