Can Molly Live With Guppy?

• Both are livebearers that prefer harder, more alkaline water
• Mollies are larger and more active than guppies

Compatibility Score Breakdown

Minimum Tank Size

At least 25 gallons for this combination.

Setup Tips

• Use hard, alkaline water if possible
• Provide swimming space for mollies
• Monitor male chasing behavior

Works Best If

• The tank is at least 25 gallons and fully cycled.
• Both species have hiding space and are introduced with close observation.
• Water temperature and pH stay inside the overlap shown in the score breakdown.

Main Risks

• Mollies may outcompete guppies in small tanks
• Breeding can increase stocking quickly

Avoid This Pairing If

• The tank is smaller than the recommended minimum.
• Either species is already showing stress, hiding, or fin damage.
• You cannot separate the fish quickly if chasing, nipping, or bullying starts.

Frequently Asked Questions