Species › Livebearers

Molly tank mates and minimum tank size

Poecilia sphenops

Mollies grow to 8 cm (3.1 in). They need 21–28 °C (70–82 °F) and pH 7.5–8.2.

Minimum tank

81 L (21 US gal), at least 90 cm (35 in) long

Adult size

8 cm (3.1 in)

Temperature

21–28 °C (70–82 °F)

pH

pH 7.5–8.2

Group

no minimum

Molly minimum tank size

Mollies need at least 81 L (21 US gal), in a tank at least 90 cm (35 in) long.

That is the largest minimum among the sources below. The planner also checks the tank length against the adult size of 8 cm (3.1 in): a tank shorter than 4 times that is cramped (32 cm (13 in)).

Molly tank mates

Each of the other 52 species in this reference, judged against mollies by the same rules as the compatibility checker. A guide, not a guarantee.

Compatible (15)

• Boeseman's rainbowfish
• Bronze corydoras
• Cherry barb
• Guppy
• Mystery snail
• Nerite snail
• Paradise fish
• Pearl gourami
• Platy
• Rosy barb
• Siamese algae eater
• Swordtail
• Tiger barb
• White cloud mountain minnow
• Zebra danio

With care (18)

• BettaThe only pH that suits both is pH 7.5, set by mollies and bettas. That leaves no margin. Bettas are usually best kept alone. Some accept calm tank mates such as mollies, many do not.
• Black neon tetraThe only pH that suits both is pH 7.5, set by mollies and black neon tetras. That leaves no margin.
• Bristlenose plecoThe only pH that suits both is pH 7.5, set by mollies and bristlenose plecos. That leaves no margin.
• Celestial pearl danioThe only pH that suits both is pH 7.5, set by mollies and celestial pearl danios. That leaves no margin. Celestial pearl danios (2.1 cm) are shy and easily intimidated by much larger mollies (8 cm).
• Cherry shrimpMollies (8 cm) usually leave adult cherry shrimp (4 cm) alone but eat the young.
• Common plecoThe only pH that suits both is pH 7.5, set by mollies and common plecos. That leaves no margin.
• Congo tetraThe only pH that suits both is pH 7.5, set by mollies and Congo tetras. That leaves no margin.
• Dwarf gouramiThe only pH that suits both is pH 7.5, set by mollies and dwarf gouramis. That leaves no margin.
• Endler's livebearerEndler's livebearers (2.5 cm) are shy and easily intimidated by much larger mollies (8 cm).
• Glowlight tetraThe only pH that suits both is pH 7.5, set by mollies and glowlight tetras. That leaves no margin.
• GoldfishThe only temperature that suits both is 21–21.1 °C (70–70 °F), set by mollies and goldfish. That leaves no margin.
• Honey gouramiThe only pH that suits both is pH 7.5, set by mollies and honey gouramis. That leaves no margin.
• KribensisThe only pH that suits both is pH 7.5, set by mollies and kribensis. That leaves no margin.
• Lemon tetraThe only pH that suits both is pH 7.5, set by mollies and lemon tetras. That leaves no margin.
• OtocinclusThe only pH that suits both is pH 7.5, set by mollies and otocinclus. That leaves no margin.
• Red tail sharkThe only pH that suits both is pH 7.5, set by mollies and red tail sharks. That leaves no margin.
• Serpae tetraThe only pH that suits both is pH 7.5, set by mollies and serpae tetras. That leaves no margin.
• Yoyo loachThe only pH that suits both is pH 7.5, set by mollies and yoyo loaches. That leaves no margin.

Not compatible (19)

• AngelfishMollies need pH 7.5–8.2; angelfish need pH 6.8–7.4. No pH suits both.
• Black skirt tetraMollies need pH 7.5–8.2; black skirt tetras need pH 6.0–7.0. No pH suits both.
• Cardinal tetraMollies need pH 7.5–8.2; cardinal tetras need pH 4.0–6.0. No pH suits both.
• Chili rasboraMollies need pH 7.5–8.2; chili rasboras need pH 6.5–7.0. No pH suits both.
• Clown loachMollies need pH 7.5–8.2; clown loaches need pH 5.0–7.0. No pH suits both.
• Cockatoo dwarf cichlidMollies need pH 7.5–8.2; cockatoo dwarf cichlids need pH 6.0. No pH suits both.
• Convict cichlidConvict cichlids are aggressive and best kept in a tank of their own; they attack fish several times their size, so mollies would be harassed.
• DiscusMollies need pH 7.5–8.2; discus need pH 5.0–7.0. No pH suits both.
• Ember tetraMollies need pH 7.5–8.2; ember tetras need pH 5.0–7.0. No pH suits both. Ember tetras (2 cm) are shy and easily intimidated by much larger mollies (8 cm).
• German blue ramMollies need pH 7.5–8.2; German blue rams need pH 5.0–6.0. No pH suits both.
• Glass catfishMollies need pH 7.5–8.2; glass catfish need pH 4.0–7.0. No pH suits both.
• Harlequin rasboraMollies need pH 7.5–8.2; harlequin rasboras need pH 5.0–7.0. No pH suits both.
• Kuhli loachMollies need pH 7.5–8.2; kuhli loaches need pH 5.5–6.5. No pH suits both.
• Neon tetraMollies need pH 7.5–8.2; neon tetras need pH 5.0–7.0. No pH suits both.
• OscarOscars grow to 46 cm and eat animals they can swallow; mollies grow to 8 cm. The only pH that suits both is pH 7.5, set by mollies and oscars. That leaves no margin.
• Panda corydorasMollies need pH 7.5–8.2; panda corydoras need pH 6.0–7.4. No pH suits both.
• Peppered corydorasMollies need pH 7.5–8.2; peppered corydoras need pH 6.0–7.0. No pH suits both.
• Pygmy corydorasMollies need pH 7.5–8.2; pygmy corydoras need pH 6.4–7.4. No pH suits both.
• Rummy-nose tetraMollies need pH 7.5–8.2; rummy-nose tetras need pH 5.5–6.0. No pH suits both.

Sources

Where sources differ, the value shown is computed as the most cautious one.

Check against another species Plan a tank