What size tank does a Balloon Molly need?

Balloon Molly needs a minimum of 10 gallons, with 15 gallons recommended. They are middle swimmers. Keep in groups of 3+.

Is Balloon Molly good for beginners?

Balloon Molly is rated "beginner" difficulty (1/5). Great for beginners.

What fish are compatible with Balloon Molly?

Balloon Molly is peaceful. Compatible tank mates include other peaceful fish with similar water parameters (pH 7-8.5, temp 72-82°F).

Balloon Molly

Poecilia sphenops var.

Family: Poeciliidae • Origin: Various

Balloon Molly (Poecilia sphenops var.) is a peaceful livebearer reaching 3 inches. Keep in groups of 3+. Minimum tank size: 10 gallons.

Min Tank

10 gal

Max Size

Temperature

72-82°F

7-8.5

Lifespan

5 years

School Size

Swim Level

middle

Hardness

5-15 dGH

peacefulbeginneromnivoreschooling

Is Balloon Molly Right for Your Tank?

Balloon Molly is an excellent choice for beginners — rated "beginner" difficulty (1/5). They're hardy, forgiving of minor water parameter fluctuations, and generally easy to feed. At just 10 gallons minimum, they work well in nano tanks and smaller setups.

With a peaceful temperament, Balloon Molly makes a great community fish. They coexist well with other non-aggressive species of similar size. This is a schooling species — keep at least 3 together, or they may become stressed and display abnormal behavior. Expected lifespan: 5 years with proper care.

Common Mistakes with Balloon Molly

✗

Keeping fewer than 3 together

Balloon Molly is a schooling species — they need a group of at least 3 to feel secure. Lone or paired individuals become stressed, hide constantly, and may develop health issues or aggression.

✗

Relying on a heater without a thermometer

Balloon Molly needs 72–82°F. Heaters malfunction or drift over time — always use a separate thermometer to verify. Temperature swings of even 3–4°F can trigger stress and disease, particularly ich.

✗

Putting them in a tank under 10 gallons

While 10 gallons is the minimum, nano tanks require more frequent water changes and leave less room for error. A slightly larger tank (15 gal) is much more forgiving.