Siamese Algae Eater
Crossocheilus oblongus
Family: Cyprinidae • Origin: Southeast Asia
The Siamese Algae Eater is the only common fish that eats black beard algae (BBA). Essential for planted tank keepers battling BBA.
Is Siamese Algae Eater Right for Your Tank?
Siamese Algae Eater is an excellent choice for beginners — rated "beginner" difficulty (2/5). They're hardy, forgiving of minor water parameter fluctuations, and generally easy to feed. A 30-gallon tank minimum is standard — most community setups will accommodate them.
With a peaceful temperament, Siamese Algae Eater makes a great community fish. They coexist well with other non-aggressive species of similar size. Expected lifespan: 10 years with proper care.
Common Mistakes with Siamese Algae Eater
Relying on a heater without a thermometer
Siamese Algae Eater needs 75–82°F. Heaters malfunction or drift over time — always use a separate thermometer to verify. Temperature swings of even 3–4°F can trigger stress and disease, particularly ich.
Putting them in a tank under 30 gallons
Many beginners underestimate tank size needs. Siamese Algae Eater requires at least 30 gallons — ideally 55. Cramped tanks lead to stunted growth, aggression, and poor water quality.
Skipping the quarantine period
Even healthy-looking fish can carry parasites or disease. Quarantine new Siamese Algae Eater for 2–4 weeks in a separate tank before adding to your main aquarium.
Care Tips
- • Only fish that eats black beard algae
- • Grows to 6 inches — needs space
- • May become lazy about algae with age
- • Avoid Chinese Algae Eater (different fish!)
- • Active swimmer — needs open space
Feeding: Algae (including black beard algae), blanched vegetables, algae wafers.
Compatibility Notes: Only true algae eater that eats black beard algae. Gets large — needs space. Can become less effective at algae as it ages.
Tank Setup & Water Parameters
Tank Requirements
- Minimum Tank Size
- 30 gallons
- Recommended Tank Size
- 55 gallons
- Swimming Level
- bottom
Water Parameters
- Temperature
- 75–82°F
- pH Range
- 6.5–7.5
- Hardness (dGH)
- 5–15
- Water Type
- freshwater
Behavior & Temperament
- Temperament
- peaceful
- Aggression Level
- 2/5
- Schooling
- No
- Territorial
- No
- Fin Nipper
- No
- Predatory
- No
- Diet Type
- herbivore
- Growth Rate
- moderate
Only true algae eater that eats black beard algae. Gets large — needs space. Can become less effective at algae as it ages.
Breeding
- Breeding Type
- egg layer
- Breeding Difficulty
- very difficult
- Lifespan
- 10 years
Ideal For
Compatible Tank Mates
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