Aquariumtetra · freshwater
Congo Tetra: adult size, tank size & tankmates
The Congo Tetra (Phenacogrammus interruptus) grows to about 3.8 in (8 cm SL). It needs a tank at least 48 inches long and about 30 gallons. Keep at least 6 together, at 73–82°F.
How big it really gets
Drawn to scale against common tank lengths. Green bars meet the minimum tank length from our sources.
Will it fit your tank?
Quick facts
- Adult size
- 3.8 in (8 cm SL)
- Minimum tank
- 48 inches long and about 30 gallons
- Temperature
- 73–82°F
- pH
- 6–7.5
- Hardness
- 3–18 dGH
- Group size
- 6+
- With other fish
- peaceful
- With its own kind
- peaceful
- Swims
- middle of the tank
- Diet
- omnivore
- Care level
- intermediate
- Lifespan
- not stated in sources
Watch for: long fins that nippers target · eats shrimp · jumps, so keep a lid
Congo Tetra tankmates
Checked with the same rules as our tank builder: temperature overlap, pH and hardness, predation and mouth size, fin-nipping and temperament. Tank size is left out here; check it in the builder.
Good tankmates
- Neon TetraAdult ~1.4 in · 70–77°F
- Cardinal TetraAdult ~1.7 in · 73–84°F
- Harlequin RasboraAdult ~2.1 in · 70–82°F
- Ember TetraAdult ~0.9 in · 68–82°F
- Chili RasboraAdult ~0.9 in · 68–82°F
- Celestial Pearl DanioAdult ~1 in · 68–79°F
- Cherry BarbAdult ~2.4 in · 68–81°F
- Rummy-nose TetraAdult ~2.4 in · 73–79°F
- Black Neon TetraAdult ~1.7 in · 73–82°F
- Glowlight TetraAdult ~1.9 in · 75–82°F
Use caution
- German Blue RamNeeds careCongo Tetra and German Blue Ram only share 81–82°F. That's a tight window.
- AngelfishNeeds careAngelfish can bully smaller, peaceful Congo Tetra.
- Nerite SnailCongo Tetra (pH 6–7.5) and Nerite Snail (pH 8–8.4) prefer different pH.
- Mystery SnailCongo Tetra (pH 6–7.5) and Mystery Snail (pH unknown) prefer different pH.
- Zebra DanioNeeds careZebra Danio nips fins, and Congo Tetra has long fins.
- Tiger BarbNeeds careTiger Barb nips fins, and Congo Tetra has long fins.
- Boesemani RainbowfishCongo Tetra and Boesemani Rainbowfish only share 81–82°F. That's a tight window.
- Black Skirt TetraBlack Skirt Tetra nips fins, and Congo Tetra has long fins.
Avoid
- Cherry ShrimpCongo Tetra will eat Cherry Shrimp.
- Amano ShrimpCongo Tetra will eat Amano Shrimp.
- White Cloud Mountain MinnowNeeds careCongo Tetra (73–82°F) and White Cloud Mountain Minnow (57–72°F) need different temperatures.
- Bamboo ShrimpCongo Tetra will eat Bamboo Shrimp.
- Chinese Algae EaterOutgrows tanksChinese Algae Eater is aggressive toward tankmates. Congo Tetra is peaceful.
- Convict CichlidNeeds careConvict Cichlid nips fins, and Congo Tetra has long fins.
- Crystal Red ShrimpCongo Tetra will eat Crystal Red Shrimp.
- Fancy GoldfishOutgrows tanksCongo Tetra (73–82°F) and Fancy Goldfish (50–70°F) need different temperatures.
All 105 species we checked against the Congo Tetra
| Species | Verdict | Why |
|---|---|---|
| African Dwarf Frog | Compatible | No conflicts found |
| Assassin Snail | Compatible | No conflicts found |
| Bala Shark | Compatible | No conflicts found |
| Betta | Compatible | No conflicts found |
| Black Neon Tetra | Compatible | No conflicts found |
| Bleeding Heart Tetra | Compatible | No conflicts found |
| Bolivian Ram | Compatible | No conflicts found |
| Bristlenose Pleco | Compatible | No conflicts found |
| Bronze Cory | Compatible | No conflicts found |
| Bumblebee Goby | Compatible | No conflicts found |
| Cardinal Tetra | Compatible | No conflicts found |
| Celestial Pearl Danio | Compatible | No conflicts found |
| Cherry Barb | Compatible | No conflicts found |
| Chili Rasbora | Compatible | No conflicts found |
| Clown Killifish | Compatible | No conflicts found |
| Clown Loach | Compatible | No conflicts found |
| Clown Pleco | Compatible | No conflicts found |
| Cockatoo Dwarf Cichlid | Compatible | No conflicts found |
| Common / Comet Goldfish | Compatible | No conflicts found |
| Common Pleco | Compatible | No conflicts found |
| Denison Barb | Compatible | No conflicts found |
| Discus | Compatible | No conflicts found |
| Dwarf Gourami | Compatible | No conflicts found |
| Dwarf Neon Rainbowfish | Compatible | No conflicts found |
| Ember Tetra | Compatible | No conflicts found |
| Endler's Livebearer | Compatible | No conflicts found |
| Forktail Blue-eye | Compatible | No conflicts found |
| Giant Danio | Compatible | No conflicts found |
| Glass Catfish | Compatible | No conflicts found |
| Glowlight Tetra | Compatible | No conflicts found |
| Gold Barb | Compatible | No conflicts found |
| Guppy | Compatible | No conflicts found |
| Harlequin Rasbora | Compatible | No conflicts found |
| Head-and-tail-light Tetra | Compatible | No conflicts found |
| Hillstream Loach | Compatible | No conflicts found |
| Honey Gourami | Compatible | No conflicts found |
| Japanese Trapdoor Snail | Compatible | No conflicts found |
| Julii Cory | Compatible | No conflicts found |
| Kribensis | Compatible | No conflicts found |
| Kuhli Loach | Compatible | No conflicts found |
| Lambchop Rasbora | Compatible | No conflicts found |
| Lemon Tetra | Compatible | No conflicts found |
| Malaysian Trumpet Snail | Compatible | No conflicts found |
| Marbled Hatchetfish | Compatible | No conflicts found |
| Molly | Compatible | No conflicts found |
| Moonlight Gourami | Compatible | No conflicts found |
| Neon Tetra | Compatible | No conflicts found |
| Odessa Barb | Compatible | No conflicts found |
| Otocinclus | Compatible | No conflicts found |
| Panda Cory | Compatible | No conflicts found |
| Pearl Danio | Compatible | No conflicts found |
| Pearl Gourami | Compatible | No conflicts found |
| Peppered Cory | Compatible | No conflicts found |
| Platy | Compatible | No conflicts found |
| Pristella Tetra | Compatible | No conflicts found |
| Pygmy Cory | Compatible | No conflicts found |
| Ramshorn Snail | Compatible | No conflicts found |
| Rosy Barb | Compatible | No conflicts found |
| Rummy-nose Tetra | Compatible | No conflicts found |
| Scissortail Rasbora | Compatible | No conflicts found |
| Siamese Algae Eater | Compatible | No conflicts found |
| Silver Hatchetfish | Compatible | No conflicts found |
| Sparkling Gourami | Compatible | No conflicts found |
| Sterbai Cory | Compatible | No conflicts found |
| Swordtail | Compatible | No conflicts found |
| Tinfoil Barb | Compatible | No conflicts found |
| Upside-down Catfish | Compatible | No conflicts found |
| Variatus Platy | Compatible | No conflicts found |
| Angelfish | Caution | Angelfish can bully smaller, peaceful Congo Tetra. |
| Black Skirt Tetra | Caution | Black Skirt Tetra nips fins, and Congo Tetra has long fins. |
| Blood Parrot Cichlid | Caution | Blood Parrot Cichlid can bully smaller, peaceful Congo Tetra. |
| Boesemani Rainbowfish | Caution | Congo Tetra and Boesemani Rainbowfish only share 81–82°F. That's a tight window. |
| Buenos Aires Tetra | Caution | Buenos Aires Tetra nips fins, and Congo Tetra has long fins. |
| Diamond Tetra | Caution | Diamond Tetra nips fins, and Congo Tetra has long fins. |
| Electric Blue Acara | Caution | Electric Blue Acara can bully smaller, peaceful Congo Tetra. |
| Electric Yellow Lab | Caution | Electric Yellow Lab nips fins, and Congo Tetra has long fins.; Congo Tetra (pH 6–7.5) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH. |
| Firemouth Cichlid | Caution | Firemouth Cichlid can bully smaller, peaceful Congo Tetra. |
| German Blue Ram | Caution | Congo Tetra and German Blue Ram only share 81–82°F. That's a tight window. |
| Kissing Gourami | Caution | Kissing Gourami can bully smaller, peaceful Congo Tetra. |
| Mystery Snail | Caution | Congo Tetra (pH 6–7.5) and Mystery Snail (pH unknown) prefer different pH.; Congo Tetra (3–18 dGH) and Mystery Snail (unknown dGH) prefer different water hardness. |
| Nerite Snail | Caution | Congo Tetra (pH 6–7.5) and Nerite Snail (pH 8–8.4) prefer different pH. |
| Pea Puffer | Caution | Pea Puffer nips fins, and Congo Tetra has long fins. |
| Penguin Tetra | Caution | Penguin Tetra nips fins, and Congo Tetra has long fins. |
| Pictus Catfish | Caution | Pictus Catfish can bully smaller, peaceful Congo Tetra. |
| Rainbow Shark | Caution | Rainbow Shark can bully smaller, peaceful Congo Tetra. |
| Red-Tail Shark | Caution | Red-Tail Shark can bully smaller, peaceful Congo Tetra. |
| Serpae Tetra | Caution | Serpae Tetra nips fins, and Congo Tetra has long fins. |
| Silver Tip Tetra | Caution | Silver Tip Tetra nips fins, and Congo Tetra has long fins. |
| Three-spot Gourami | Caution | Three-spot Gourami can bully smaller, peaceful Congo Tetra. |
| Tiger Barb | Caution | Tiger Barb nips fins, and Congo Tetra has long fins. |
| Weather Loach | Caution | Congo Tetra and Weather Loach only share 73–74°F. That's a tight window. |
| Yoyo Loach | Caution | Yoyo Loach nips fins, and Congo Tetra has long fins.; Yoyo Loach can bully smaller, peaceful Congo Tetra. |
| Zebra Danio | Caution | Zebra Danio nips fins, and Congo Tetra has long fins. |
| Amano Shrimp | Avoid | Congo Tetra will eat Amano Shrimp. |
| Bamboo Shrimp | Avoid | Congo Tetra will eat Bamboo Shrimp. |
| Cherry Shrimp | Avoid | Congo Tetra will eat Cherry Shrimp. |
| Chinese Algae Eater | Avoid | Chinese Algae Eater is aggressive toward tankmates. Congo Tetra is peaceful. |
| Convict Cichlid | Avoid | Convict Cichlid nips fins, and Congo Tetra has long fins.; Convict Cichlid is aggressive toward tankmates. Congo Tetra is peaceful. |
| Crystal Red Shrimp | Avoid | Congo Tetra will eat Crystal Red Shrimp. |
| Fancy Goldfish | Avoid | Congo Tetra (73–82°F) and Fancy Goldfish (50–70°F) need different temperatures. |
| Ghost Shrimp | Avoid | Congo Tetra will eat Ghost Shrimp.; Ghost Shrimp nips fins, and Congo Tetra has long fins. |
| Iridescent Shark | Avoid | Iridescent Shark eats small fish, and Congo Tetra only grows to about 3.8 in. |
| Oscar | Avoid | Oscar eats small fish, and Congo Tetra only grows to about 3.8 in. |
| Paradise Fish | Avoid | Congo Tetra (73–82°F) and Paradise Fish (50–72°F) need different temperatures. |
| White Cloud Mountain Minnow | Avoid | Congo Tetra (73–82°F) and White Cloud Mountain Minnow (57–72°F) need different temperatures. |
Care notes
Needs: Male caudal and dorsal fin filaments require pristine low-nitrate water and protection from fin-nippers
Group: Open-water shoaler requiring at least 6-8 individuals; becomes skittish if numbers are low
Temperament: peaceful toward other fish, peaceful toward its own kind. Lives in the middle of the tank.
Common questions
How big does a Congo Tetra get?
About 3.8 inches (8 cm SL) as an adult, according to seriouslyfish.com.
What size tank does a Congo Tetra need?
At least 48 inches long and about 30 gallons. The smallest standard tank that meets that is a 55 gallon.
How many Congo Tetras should be kept together?
At least 6. Open-water shoaler requiring at least 6-8 individuals; becomes skittish if numbers are low
What fish can live with a Congo Tetra?
Species that passed every check include Neon Tetra, Cardinal Tetra, Harlequin Rasbora, Ember Tetra, Chili Rasbora, Celestial Pearl Danio.
Gear for a Congo Tetra setup
TankSmallest standard tank that meets its minimum: 55 gallon (48 in long).Find on Amazon →HeaterAbout 300 W for 55 gallons, holding 73–82°F.Find on Amazon →LidIt jumps. A full lid keeps it in the tank.Find on Amazon →FoodA quality flake or micro-pellet as a staple.Find on Amazon →Test kitCheck ammonia, nitrite and pH. Cycle the tank before adding fish.Find on Amazon →
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Related guides
Sources
Values come from these pages, in our own words. Status: verified. Last reviewed 2026-10-12.
- seriouslyfish.com /species/phenacogrammus-interruptus
- fishbase.se /summary/Phenacogrammus-interruptus.html