Can Balloon Molly and Glass Catfish Live Together?

Not Recommended

Balloon Molly and Glass Catfish are not recommended as tank mates due to incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Balloon Molly

Poecilia latipinna hybrid

Glass Catfish

Kryptopterus vitreolus

🐠Family Group
Balloon Molly
Livebearers
Glass Catfish
Catfish
Temperament
Balloon Molly
Mostly Peaceful (3/10)
Glass Catfish
Peaceful (1/10)
Temperature
✓ Compatible
Balloon Molly
24–28°C
Glass Catfish
24–28°C
pH Range
✓ Compatible
Balloon Molly
7–8.5
Glass Catfish
6–7
Hardness (dGH)
✗ No overlap
Balloon Molly
12–25
Glass Catfish
1–10
Water Type
✓ Compatible
Balloon Molly
Brackish Tolerant
Glass Catfish
Freshwater Only
Flow Preference
✓ Compatible
Balloon Molly
Low
Glass Catfish
Moderate
Min Tank Volume
Combined: 110 L
Balloon Molly
75 L
Glass Catfish
110 L
Swimming Level
Shared: 1 zone
Balloon Molly
TopMiddle
Glass Catfish
Middle
🏷️Behavior Tags
Balloon Molly
Hyperactive / Fast SwimmerFry Predator
Glass Catfish
Shy / Slow Moving (Easily Stressed)Fry Predator
Stocking calculator

Can your tank handle Balloon Molly and Glass Catfish?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Balloon Molly
Glass Catfish
Test both in my tank

Behaviour & Temperament

Balloon Molly is a generally mild-mannered species (3/10), while Glass Catfish is peaceful (1/10). This modest difference means Balloon Molly may occasionally assert dominance over Glass Catfish.

Balloon Molly and Glass Catfish both frequent the Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Water Parameters

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Balloon Molly needs 12–25 dGH while Glass Catfish requires 1–10 dGH.

Tank Setup

To house Balloon Molly and Glass Catfish together, plan for an aquarium of at least 110 litres with a minimum length of 90 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Established Algae (Otocinclus), Plants - Densely covered, Plants - Floating. Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Balloon Molly and Glass Catfish.

Show 10 more tank sizes

Frequently Asked Questions

Can Balloon Molly and Glass Catfish live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Balloon Molly and Glass Catfish need?

A minimum of 110 litres (tank length at least 90 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Balloon Molly and Glass Catfish together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Balloon Molly or Glass Catfish aggressive?

Balloon Molly is generally mild-mannered (3/10) and Glass Catfish is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Balloon Molly and Glass Catfish need?

Both species overlap in the 7–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.


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