Can Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) Live Together?

🟢Ideal Tank Mates

Yes, Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) are ideal tank mates. Both species share compatible water parameters and peaceful temperaments, making them well-suited for a community aquarium. A minimum tank size of 540 litres is recommended.


At a Glance

Molly (Sailfin/Black/Dalmatian)

Poecilia sphenops

Scat (Brackish)

Scatophagus argus

🐠Family Group
Molly (Sailfin/Black/Dalmatian)
Livebearers
Scat (Brackish)
Oddballs
Temperament
Molly (Sailfin/Black/Dalmatian)
Mostly Peaceful (3/10)
Scat (Brackish)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
24–28°C
Scat (Brackish)
20–28°C
pH Range
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
7.5–8.5
Scat (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
12–30
Scat (Brackish)
12–30
Water Type
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
Brackish Tolerant
Scat (Brackish)
Brackish Required
Flow Preference
✓ Compatible
Molly (Sailfin/Black/Dalmatian)
Moderate
Scat (Brackish)
High
Min Tank Volume
Combined: 540 L
Molly (Sailfin/Black/Dalmatian)
75 L
Scat (Brackish)
450 L
Swimming Level
Shared: 1 zone
Molly (Sailfin/Black/Dalmatian)
TopMiddle
Scat (Brackish)
MiddleBottom
🏷️Behavior Tags
Molly (Sailfin/Black/Dalmatian)
Hyperactive / Fast SwimmerFry PredatorAggressive Eater (Starves shy fish)
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper

Behaviour & Temperament

Molly (Sailfin/Black/Dalmatian) is a generally mild-mannered species (3/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Scat (Brackish) may occasionally assert dominance over Molly (Sailfin/Black/Dalmatian).

Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) 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.

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 7.5 and 8.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–30 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) together, plan for an aquarium of at least 540 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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: Plants - Densely covered, Established Algae (Otocinclus), Sand (Sifters), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Scat (Brackish) is a plant destroyer, which conflicts with Molly (Sailfin/Black/Dalmatian)'s requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Find the right tank equipment

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Frequently Asked Questions

Can Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) live together?

Yes. Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) are considered ideal tank mates. Their water parameters, temperaments, and behaviour profiles are well matched for a community aquarium.

What size tank do Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) need?

A minimum of 540 litres (tank length at least 150 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 Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) 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 Molly (Sailfin/Black/Dalmatian) or Scat (Brackish) aggressive?

Molly (Sailfin/Black/Dalmatian) is generally mild-mannered (3/10) and Scat (Brackish) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Molly (Sailfin/Black/Dalmatian) and Scat (Brackish) need?

Both species overlap in the 7.5–8.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Scat (Brackish) nip Molly (Sailfin/Black/Dalmatian)'s fins?

Scat (Brackish) is a known fin nipper. If Molly (Sailfin/Black/Dalmatian) has long or flowing fins, there is a real risk of fin damage. Keeping Scat (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.


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