Can mollies live with hatchetfish?

Verdict

Yes, with care

Yes, with care. Mollies and hatchetfish 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

Hatchetfish75–81°F · pH 5.5–7.5

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 75–81°F.

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	Hatchetfish
Temperature	72–82 °F	75–81 °F
pH	7.5–8.5	5.5–7.5
Adult size	4.0 in	1.5 in
Minimum tank	20 gal	20 gal
Temperament	Peaceful	Peaceful
Swims at	Top	Top
Group	Groups of 3+	Groups of 6+
Diet	Omnivore	Carnivore

Better tank mates for mollies

All molly tank mates

Better tank mates for hatchetfish

All hatchetfish tank mates

Questions

Can mollies live with hatchetfish?

Yes, with care. Mollies and hatchetfish 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 hatchetfish?

75–81 °F. Mollies need 72–82 °F, hatchetfish need 75–81 °F.

What size tank do mollies and hatchetfish need together?

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