Can mollies live with severums?

Verdict
Yes, with care

Yes, with care. Mollies and severums can share a tank, but watch one thing. Different water: mollies want pH 7.5–8.5, severums want pH 6–7.

MollyMolly72–82°F · pH 7.5–8.5 SeverumSeverum74–84°F · pH 6–7

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 74–82°Molly 72–82°Severum 74–84°
The green band is the temperature range both can live in.
456789Molly 7.5–8.5Severum 6–7
No pH suits both. One would live in the wrong water all the time.

Size to scale

Molly · 4 inSeverum · 8 in0"1"2"3"4"5"6"7"8"
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

MollySeverum
Temperature72–82 °F74–84 °F
pH7.5–8.56–7
Adult size4.0 in8.0 in
Minimum tank20 gal55 gal
TemperamentPeacefulSemi-aggressive
Swims atTopMiddle
GroupGroups of 3+Alone or in pairs
DietOmnivoreOmnivore

Better tank mates for mollies

All molly tank mates

Better tank mates for severums

All severum tank mates

Questions

Can mollies live with severums?

Yes, with care. Mollies and severums can share a tank, but watch one thing. Different water: mollies want pH 7.5–8.5, severums want pH 6–7.

What temperature suits both mollies and severums?

74–82 °F. Mollies need 72–82 °F, severums need 74–84 °F.

What size tank do mollies and severums need together?

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