Otocinclus Catfish

Diminutive algae grazers that polish plants and glass without touching tank mates. They need a well-established tank with soft algae and should never be kept alone.

• Minimum footprint: 10 gallons; a 20+ gallon tank gives real swimming room.
• Preferred swimming zone: bottom of the water column.
• Social — keep a group of at least 6.
• Care level: moderate.

• Temperature: 72–82°F
• pH: 6–7.5
• Hardness: 2–10 dGH (Moderate)

Stable parameters matter more than perfect ones — aim for consistency before chasing an exact number.

peaceful

schoolingalgae-grazerbottom-dwellersensitive

A herbivore / grazer — it needs plant matter and algae. Offer blanched vegetables, algae wafers, and a mature tank with surfaces to graze.

• Neon Tetra
• Guppy
• Bronze Corydoras
• Harlequin Rasbora
• Zebra Danio
• Platy

A further 1 species pair with Otocinclus Catfish as conditional — workable with the right tank and precautions.

• Angelfish — Occasional chasing or fin nipping is possible.
• Electric Blue Acara — Occasional chasing or fin nipping is possible.

Standard tanks at or above the recommended 20 gallons:

• 20 gallon High 24 × 12 × 16″
• 20 gallon Long 30 × 12 × 12″
• 29 gallon 30 × 12 × 18″
• All tank sizes

• Start from a 10 gallon minimum and plan the full group size (6+) before you buy.
• Activity level is moderate, which affects how much of the tank it uses and how much it adds to the bioload.
• Zoning matters: this species lives mostly in the bottom zone, so choose tank mates that occupy other levels.

Compatibility depends on tank size, water chemistry, temperament, and adult size. Run a full check against any species in our database.

In-depth guides for Otocinclus Catfish:

• Otocinclus Catfish and Bronze CorydorasGood Match
• Otocinclus Catfish and Neon TetraGood Match

• FishBase(Scientific Database, accessed 2026-09-20)
• SeriouslyFish(Specialist Publication, accessed 2026-09-20)
• Practical Fishkeeping(Specialist Publication, accessed 2026-09-20)
• Aquarium Forge editorial guidelines(Editorial Interpretation, accessed 2026-09-22)

Data reviewed: September 2026 · Data version: 2026.11
Editorial note: Minimum tank recommendations may vary by source and husbandry approach. Our figures synthesise the sources above for planning purposes.