Can otocinclus live with mollies?

Verdict

Yes, with care

Yes, with care. Otocinclus and mollies can share a tank, but watch one thing. Water chemistry is a squeeze. The only pH that suits both is around 7.5.

Otocinclus72–79°F · pH 6–7.5

Molly72–82°F · pH 7.5–8.5

What to watch

Watch outWater chemistry is a squeeze. The only pH that suits both is around 7.5.

What works

Both are fine at 72–79°F.
They use different parts of the tank: otocinclus the bottom, mollies the top.

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

	Otocinclus	Molly
Temperature	72–79 °F	72–82 °F
pH	6–7.5	7.5–8.5
Adult size	2.0 in	4.0 in
Minimum tank	20 gal	20 gal
Temperament	Peaceful	Peaceful
Swims at	Bottom	Top
Group	Groups of 6+	Groups of 3+
Diet	Herbivore	Omnivore

Better tank mates for otocinclus

All otocinclus tank mates

Better tank mates for mollies

All molly tank mates

Questions

Can otocinclus live with mollies?

Yes, with care. Otocinclus and mollies can share a tank, but watch one thing. Water chemistry is a squeeze. The only pH that suits both is around 7.5.

What temperature suits both otocinclus and mollies?

72–79 °F. Otocinclus need 72–79 °F, mollies need 72–82 °F.

What size tank do otocinclus and mollies need together?

At least 20 gal, set by the otocinclus. Add space for each extra fish.