FishTankHelper

Otocinclus care: tank size, temperature and tankmates

By Andy · Updated November 2, 2026 · Fish profile

A small algae-eating catfish that grazes soft algae off plants and glass. Otocinclus are peaceful but delicate when new.

1.75 in
Adult size
20 gal
Smallest tank
72–79°F
Temperature
6+
Group size

Quick facts

TypeCatfish
Adult sizeAbout 1.75 inches
Smallest tank20 gallons
Temperature72–79°F
Keep6 or more
Watch forPeaceful. Keep the right group size.

How to keep them

Add them only to a tank that has been running for a few months and has algae to eat, and give algae wafers or blanched zucchini too.

Like every fish, they need a cycled tank, a heater set inside their range, and a weekly water change of about 25%. Test for ammonia, nitrite and nitrate before you add them. New to this? Start with how to cycle a fish tank.

Tankmates

Good tankmates

Neon tetra · Cardinal tetra · Ember tetra · Rummynose tetra · Black skirt tetra · Serpae tetra · Harlequin rasbora · Zebra danio · Cherry barb · Tiger barb · Platy · Guppy · Endler's livebearer · Molly · Swordtail · Betta (male) · Honey gourami · Dwarf gourami · Pearl gourami · Corydoras (bronze or peppered) · Pygmy corydoras · Kuhli loach · Bristlenose pleco · Cherry shrimp · Amano shrimp · Nerite snail · Mystery snail

Possible, with care

Avoid

Check a whole tank in the fish compatibility checker, or see if they fit with the stocking calculator.

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