Can rainbow sharks live with mollies?

Verdict
Yes, with care

Yes, with care. Rainbow sharks 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 to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–80°Rainbow shark 72–80°Molly 72–82°
The green band is the temperature range both can live in.
456789Both: 7.5Rainbow shark 6.5–7.5Molly 7.5–8.5
The green band is the pH both tolerate.

Size to scale

Rainbow shark · 6 inMolly · 4 in0"1"2"3"4"5"6"
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

Rainbow sharkMolly
Temperature72–80 °F72–82 °F
pH6.5–7.57.5–8.5
Adult size6.0 in4.0 in
Minimum tank55 gal20 gal
TemperamentSemi-aggressivePeaceful
Swims atBottomTop
GroupOne per tankGroups of 3+
DietOmnivoreOmnivore

Better tank mates for rainbow sharks

All rainbow shark tank mates

Better tank mates for mollies

All molly tank mates

Questions

Can rainbow sharks live with mollies?

Yes, with care. Rainbow sharks 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 rainbow sharks and mollies?

72–80 °F. Rainbow sharks need 72–80 °F, mollies need 72–82 °F.

What size tank do rainbow sharks and mollies need together?

At least 55 gal, set by the rainbow shark. Add space for each extra fish.