Aquariumcatfish · freshwater
Julii Cory: adult size, tank size & tankmates
The Julii Cory (Corydoras trilineatus) grows to about 2.6 in (5.5 cm SL). It needs a tank at least 18 inches long and about 11 gallons. Keep at least 6 together, at 72–79°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
- 2.6 in (5.5 cm SL)
- Minimum tank
- 18 inches long and about 11 gallons
- Temperature
- 72–79°F
- pH
- 5.8–7.2
- Hardness
- 1–12 dGH
- Group size
- 6+
- With other fish
- peaceful
- With its own kind
- peaceful
- Swims
- bottom of the tank
- Diet
- omnivore
- Care level
- beginner
- Lifespan
- not stated in sources
Watch for: may eat baby shrimp
Julii Cory 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
- Endler's LivebearerNeeds careJulii Cory (1–12 dGH) and Endler's Livebearer (15–35 dGH) prefer different water hardness.
- Dwarf GouramiNeeds careDwarf Gourami can bully smaller, peaceful Julii Cory.
- AngelfishNeeds careAngelfish can bully smaller, peaceful Julii Cory.
- Cherry ShrimpJulii Cory may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Amano ShrimpJulii Cory may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Nerite SnailJulii Cory (pH 5.8–7.2) and Nerite Snail (pH 8–8.4) prefer different pH.
- Mystery SnailJulii Cory (pH 5.8–7.2) and Mystery Snail (pH unknown) prefer different pH.
- MollyNeeds careJulii Cory (1–12 dGH) and Molly (15–30 dGH) prefer different water hardness.
Avoid
- German Blue RamNeeds careJulii Cory (72–79°F) and German Blue Ram (81–86°F) need different temperatures.
- Boesemani RainbowfishJulii Cory (72–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.
- Chinese Algae EaterOutgrows tanksChinese Algae Eater grows 5× longer than Julii Cory and may treat it as food.
- Convict CichlidNeeds careConvict Cichlid is aggressive toward tankmates. Julii Cory is peaceful.
- Fancy GoldfishOutgrows tanksJulii Cory (72–79°F) and Fancy Goldfish (50–70°F) need different temperatures.
- Iridescent SharkOutgrows tanksIridescent Shark eats small fish, and Julii Cory only grows to about 2.6 in.
- OscarOutgrows tanksOscar eats small fish, and Julii Cory only grows to about 2.6 in.
All 105 species we checked against the Julii Cory
| Species | Verdict | Why |
|---|---|---|
| African Dwarf Frog | Compatible | No conflicts found |
| Bala Shark | Compatible | No conflicts found |
| Betta | Compatible | No conflicts found |
| Black Neon Tetra | Compatible | No conflicts found |
| Black Skirt 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 |
| Buenos Aires Tetra | 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 |
| Congo Tetra | Compatible | No conflicts found |
| Denison Barb | Compatible | No conflicts found |
| Diamond Tetra | Compatible | No conflicts found |
| Dwarf Neon Rainbowfish | Compatible | No conflicts found |
| Ember Tetra | 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 |
| 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 |
| 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 |
| Pea Puffer | Compatible | No conflicts found |
| Pearl Danio | Compatible | No conflicts found |
| Pearl Gourami | Compatible | No conflicts found |
| Penguin Tetra | 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 |
| Serpae Tetra | Compatible | No conflicts found |
| Siamese Algae Eater | Compatible | No conflicts found |
| Silver Hatchetfish | Compatible | No conflicts found |
| Silver Tip Tetra | Compatible | No conflicts found |
| Sparkling Gourami | Compatible | No conflicts found |
| Sterbai Cory | Compatible | No conflicts found |
| Swordtail | Compatible | No conflicts found |
| Tiger Barb | Compatible | No conflicts found |
| Tinfoil Barb | Compatible | No conflicts found |
| Upside-down Catfish | Compatible | No conflicts found |
| Weather Loach | Compatible | No conflicts found |
| Zebra Danio | Compatible | No conflicts found |
| Amano Shrimp | Caution | Julii Cory may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Angelfish | Caution | Angelfish can bully smaller, peaceful Julii Cory. |
| Assassin Snail | Caution | Julii Cory (pH 5.8–7.2) and Assassin Snail (pH 7.5–8) prefer different pH. |
| Bamboo Shrimp | Caution | Julii Cory may eat baby Bamboo Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Blood Parrot Cichlid | Caution | Blood Parrot Cichlid can bully smaller, peaceful Julii Cory. |
| Cherry Shrimp | Caution | Julii Cory may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Crystal Red Shrimp | Caution | Julii Cory may eat baby Crystal Red Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Discus | Caution | Julii Cory and Discus only share 79–79°F. That's a tight window. |
| Dwarf Gourami | Caution | Dwarf Gourami can bully smaller, peaceful Julii Cory. |
| Electric Blue Acara | Caution | Electric Blue Acara can bully smaller, peaceful Julii Cory. |
| Electric Yellow Lab | Caution | Electric Yellow Lab can bully smaller, peaceful Julii Cory.; Julii Cory (pH 5.8–7.2) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH. |
| Endler's Livebearer | Caution | Julii Cory (1–12 dGH) and Endler's Livebearer (15–35 dGH) prefer different water hardness. |
| Firemouth Cichlid | Caution | Firemouth Cichlid can bully smaller, peaceful Julii Cory. |
| Forktail Blue-eye | Caution | Julii Cory (1–12 dGH) and Forktail Blue-eye (15–30 dGH) prefer different water hardness. |
| Ghost Shrimp | Caution | Julii Cory may eat baby Ghost Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Kissing Gourami | Caution | Kissing Gourami grows 5× longer than Julii Cory and may treat it as food.; Kissing Gourami can bully smaller, peaceful Julii Cory. |
| Molly | Caution | Julii Cory (1–12 dGH) and Molly (15–30 dGH) prefer different water hardness. |
| Mystery Snail | Caution | Julii Cory (pH 5.8–7.2) and Mystery Snail (pH unknown) prefer different pH.; Julii Cory (1–12 dGH) and Mystery Snail (unknown dGH) prefer different water hardness. |
| Nerite Snail | Caution | Julii Cory (pH 5.8–7.2) and Nerite Snail (pH 8–8.4) prefer different pH. |
| Paradise Fish | Caution | Julii Cory and Paradise Fish only share 72–72°F. That's a tight window. |
| Pictus Catfish | Caution | Pictus Catfish can bully smaller, peaceful Julii Cory. |
| Rainbow Shark | Caution | Rainbow Shark can bully smaller, peaceful Julii Cory. |
| Red-Tail Shark | Caution | Red-Tail Shark can bully smaller, peaceful Julii Cory. |
| Three-spot Gourami | Caution | Three-spot Gourami can bully smaller, peaceful Julii Cory. |
| Variatus Platy | Caution | Julii Cory (1–12 dGH) and Variatus Platy (14–30 dGH) prefer different water hardness. |
| White Cloud Mountain Minnow | Caution | Julii Cory and White Cloud Mountain Minnow only share 72–72°F. That's a tight window. |
| Yoyo Loach | Caution | Yoyo Loach can bully smaller, peaceful Julii Cory. |
| Boesemani Rainbowfish | Avoid | Julii Cory (72–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures. |
| Chinese Algae Eater | Avoid | Chinese Algae Eater grows 5× longer than Julii Cory and may treat it as food.; Chinese Algae Eater is aggressive toward tankmates. Julii Cory is peaceful. |
| Convict Cichlid | Avoid | Convict Cichlid is aggressive toward tankmates. Julii Cory is peaceful. |
| Fancy Goldfish | Avoid | Julii Cory (72–79°F) and Fancy Goldfish (50–70°F) need different temperatures. |
| German Blue Ram | Avoid | Julii Cory (72–79°F) and German Blue Ram (81–86°F) need different temperatures. |
| Iridescent Shark | Avoid | Iridescent Shark eats small fish, and Julii Cory only grows to about 2.6 in. |
| Oscar | Avoid | Oscar eats small fish, and Julii Cory only grows to about 2.6 in. |
Care notes
Needs: Fine sand substrate required to safeguard sensory barbels; sensitive to accumulated organic waste in substrate.
Group: Social shoaling species; maintain in groups of 6 or more conspecifics.
Temperament: peaceful toward other fish, peaceful toward its own kind. Lives in the bottom of the tank.
Common questions
How big does a Julii Cory get?
About 2.6 inches (5.5 cm SL) as an adult, according to seriouslyfish.com.
What size tank does a Julii Cory need?
At least 18 inches long and about 11 gallons. The smallest standard tank that meets that is a 20 gallon long.
How many Julii Corys should be kept together?
At least 6. Social shoaling species; maintain in groups of 6 or more conspecifics.
What fish can live with a Julii Cory?
Species that passed every check include Neon Tetra, Cardinal Tetra, Harlequin Rasbora, Ember Tetra, Chili Rasbora, Celestial Pearl Danio.
Gear for a Julii Cory setup
TankSmallest standard tank that meets its minimum: 20 gallon long (30 in long).Find on Amazon →HeaterAbout 100 W for 20 gallons, holding 72–79°F.Find on Amazon →SandSoft sand protects barbels and lets it sift.Find on Amazon →FoodSinking food reaches the bottom before tankmates grab it.Find on Amazon →Test kitCheck ammonia, nitrite and pH. Cycle the tank before adding fish.Find on Amazon →
As an Amazon Associate, AquariumSetup earns from qualifying purchases. Links open Amazon search results so you can compare current options.
Related guides
Sources
Values come from these pages, in our own words. Status: verified. Last reviewed 2026-10-12.
- seriouslyfish.com /species/hoplisoma-trilineatum