Aquariumshark & minnow · freshwater
Siamese Algae Eater: adult size, tank size & tankmates
The Siamese Algae Eater (Crossocheilus langei) grows to about 7.1 in (15 cm SL). It needs a tank at least 60 inches long and about 80 gallons. Keep at least 6 together, at 68–79°F.
How big it really gets
Drawn to scale against common tank lengths. Green bars meet the minimum tank length from our sources.
Outgrows most home tanks. Sold as a small algae eater; needs a group of 6+ in a 5 ft tank.
Will it fit your tank?
Quick facts
- Adult size
- 7.1 in (15 cm SL)
- Minimum tank
- 60 inches long and about 80 gallons
- Temperature
- 68–79°F
- pH
- 6–7.5
- Hardness
- 1–15 dGH
- Group size
- 6+
- With other fish
- peaceful
- With its own kind
- semi-aggressive
- Swims
- all levels
- Diet
- omnivore
- Care level
- beginner
- Lifespan
- not stated in sources
Watch for: may eat baby shrimp · jumps, so keep a lid
Siamese Algae Eater 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
- Cherry ShrimpSiamese Algae Eater may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Amano ShrimpSiamese Algae Eater may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Nerite SnailSiamese Algae Eater (pH 6–7.5) and Nerite Snail (pH 8–8.4) prefer different pH.
- Mystery SnailSiamese Algae Eater (pH 6–7.5) and Mystery Snail (pH unknown) prefer different pH.
- Bamboo ShrimpSiamese Algae Eater may eat baby Bamboo Shrimp. Adults are usually safe, but expect fewer shrimplets.
- Crystal Red ShrimpSiamese Algae Eater may eat baby Crystal Red Shrimp. Adults are usually safe, but expect fewer shrimplets.
- DiscusNeeds careSiamese Algae Eater and Discus only share 79–79°F. That's a tight window.
- Electric Yellow LabNeeds careSiamese Algae Eater (pH 6–7.5) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH.
Avoid
- German Blue RamNeeds careSiamese Algae Eater (68–79°F) and German Blue Ram (81–86°F) need different temperatures.
- Boesemani RainbowfishSiamese Algae Eater (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures.
- Chinese Algae EaterOutgrows tanksChinese Algae Eater is aggressive toward tankmates. Siamese Algae Eater is peaceful.
- Convict CichlidNeeds careConvict Cichlid is aggressive toward tankmates. Siamese Algae Eater is peaceful.
All 105 species we checked against the Siamese Algae Eater
| Species | Verdict | Why |
|---|---|---|
| African Dwarf Frog | Compatible | No conflicts found |
| Angelfish | 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 |
| Black Skirt Tetra | Compatible | No conflicts found |
| Bleeding Heart Tetra | Compatible | No conflicts found |
| Blood Parrot Cichlid | 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 Gourami | Compatible | No conflicts found |
| Dwarf Neon Rainbowfish | Compatible | No conflicts found |
| Electric Blue Acara | Compatible | No conflicts found |
| Ember Tetra | Compatible | No conflicts found |
| Endler's Livebearer | Compatible | No conflicts found |
| Fancy Goldfish | Compatible | No conflicts found |
| Firemouth Cichlid | 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 |
| Iridescent Shark | 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 |
| Paradise Fish | 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 |
| Pictus Catfish | Compatible | No conflicts found |
| Platy | Compatible | No conflicts found |
| Pristella Tetra | Compatible | No conflicts found |
| Pygmy Cory | Compatible | No conflicts found |
| Rainbow Shark | Compatible | No conflicts found |
| Ramshorn Snail | Compatible | No conflicts found |
| Red-Tail Shark | 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 |
| 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 |
| Three-spot Gourami | Compatible | No conflicts found |
| Tiger Barb | Compatible | No conflicts found |
| Tinfoil Barb | Compatible | No conflicts found |
| Upside-down Catfish | Compatible | No conflicts found |
| Variatus Platy | Compatible | No conflicts found |
| Weather Loach | Compatible | No conflicts found |
| White Cloud Mountain Minnow | Compatible | No conflicts found |
| Yoyo Loach | Compatible | No conflicts found |
| Zebra Danio | Compatible | No conflicts found |
| Amano Shrimp | Caution | Siamese Algae Eater may eat baby Amano Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Bamboo Shrimp | Caution | Siamese Algae Eater may eat baby Bamboo Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Cherry Shrimp | Caution | Siamese Algae Eater may eat baby Cherry Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Crystal Red Shrimp | Caution | Siamese Algae Eater may eat baby Crystal Red Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Discus | Caution | Siamese Algae Eater and Discus only share 79–79°F. That's a tight window. |
| Electric Yellow Lab | Caution | Siamese Algae Eater (pH 6–7.5) and Electric Yellow Lab (pH 7.7–8.6) prefer different pH. |
| Ghost Shrimp | Caution | Siamese Algae Eater may eat baby Ghost Shrimp. Adults are usually safe, but expect fewer shrimplets. |
| Kissing Gourami | Caution | Kissing Gourami can bully smaller, peaceful Siamese Algae Eater. |
| Mystery Snail | Caution | Siamese Algae Eater (pH 6–7.5) and Mystery Snail (pH unknown) prefer different pH.; Siamese Algae Eater (1–15 dGH) and Mystery Snail (unknown dGH) prefer different water hardness. |
| Nerite Snail | Caution | Siamese Algae Eater (pH 6–7.5) and Nerite Snail (pH 8–8.4) prefer different pH. |
| Oscar | Caution | Oscar can bully smaller, peaceful Siamese Algae Eater. |
| Boesemani Rainbowfish | Avoid | Siamese Algae Eater (68–79°F) and Boesemani Rainbowfish (81–86°F) need different temperatures. |
| Chinese Algae Eater | Avoid | Chinese Algae Eater is aggressive toward tankmates. Siamese Algae Eater is peaceful. |
| Convict Cichlid | Avoid | Convict Cichlid is aggressive toward tankmates. Siamese Algae Eater is peaceful. |
| German Blue Ram | Avoid | Siamese Algae Eater (68–79°F) and German Blue Ram (81–86°F) need different temperatures. |
Care notes
Needs: High swimming length requirement; tightly fitted lid (exceptional leaping ability); supplementary grazing foods when algae is depleted.
Group: Best maintained singly or in groups of 5 or more to disperse conspecific hierarchy disputes.
Temperament: peaceful toward other fish, semi-aggressive toward its own kind. Lives in the whole tank.
Common questions
How big does a Siamese Algae Eater get?
About 7.1 inches (15 cm SL) as an adult, according to seriouslyfish.com.
What size tank does a Siamese Algae Eater need?
At least 60 inches long and about 80 gallons. The smallest standard tank that meets that is a 125 gallon.
How many Siamese Algae Eaters should be kept together?
At least 6. Best maintained singly or in groups of 5 or more to disperse conspecific hierarchy disputes.
What fish can live with a Siamese Algae Eater?
Species that passed every check include Neon Tetra, Cardinal Tetra, Harlequin Rasbora, Ember Tetra, Chili Rasbora, Celestial Pearl Danio.
Gear for a Siamese Algae Eater setup
TankSmallest standard tank that meets its minimum: 125 gallon (72 in long).Find on Amazon →HeaterAbout 2 × 300 W for 125 gallons, holding 68–79°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/crossocheilus-langei