Can mollies live with upside down catfish?

Verdict

Yes, with care

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

Molly72–82°F · pH 7.5–8.5

Upside down catfish72–79°F · pH 6–7.5

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: mollies the top, upside down catfish the bottom.

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

	Molly	Upside down catfish
Temperature	72–82 °F	72–79 °F
pH	7.5–8.5	6–7.5
Adult size	4.0 in	4.0 in
Minimum tank	20 gal	30 gal
Temperament	Peaceful	Peaceful
Swims at	Top	Bottom
Group	Groups of 3+	Groups of 3+
Diet	Omnivore	Omnivore

Better tank mates for mollies

All molly tank mates

Better tank mates for upside down catfish

All upside down catfish tank mates

Questions

Can mollies live with upside down catfish?

Yes, with care. Mollies and upside down catfish 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 mollies and upside down catfish?

72–79 °F. Mollies need 72–82 °F, upside down catfish need 72–79 °F.

What size tank do mollies and upside down catfish need together?

At least 30 gal, set by the upside down catfish. Add space for each extra fish.