Can goldfish live with otocinclus?

Verdict

No. Goldfish and otocinclus should not share a tank. Goldfish are coldwater animals (60–74°F); otocinclus need 72–79°F. They overlap only at 72–74°F, the edge of both ranges.

Goldfish60–74°F · pH 7–8

Otocinclus72–79°F · pH 6–7.5

What to watch

Deal breakerGoldfish are coldwater animals (60–74°F); otocinclus need 72–79°F. They overlap only at 72–74°F, the edge of both ranges.
Watch outAt 10 inches a goldfish can swallow a small otocinclus. Fast, alert fish usually stay out of reach.

What works

pH 7–7.5 suits both.

Water side by side

The green band is the temperature range both can live in.

The green band is the pH both tolerate.

Size to scale

Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

	Goldfish	Otocinclus
Temperature	60–74 °F	72–79 °F
pH	7–8	6–7.5
Adult size	10.0 in	2.0 in
Minimum tank	40 gal	20 gal
Temperament	Peaceful	Peaceful
Swims at	All levels	Bottom
Group	Alone or in pairs	Groups of 6+
Diet	Omnivore	Herbivore

Better tank mates for goldfish

All goldfish tank mates

Better tank mates for otocinclus

All otocinclus tank mates

Questions

Can goldfish live with otocinclus?

No. Goldfish and otocinclus should not share a tank. Goldfish are coldwater animals (60–74°F); otocinclus need 72–79°F. They overlap only at 72–74°F, the edge of both ranges.

What temperature suits both goldfish and otocinclus?

72–74 °F. Goldfish need 60–74 °F, otocinclus need 72–79 °F.

What size tank do goldfish and otocinclus need together?

At least 40 gal, set by the goldfish. Add space for each extra fish.