Can Guppy and Scat (Brackish) Live Together?

Possible with Caution

Keeping Guppy and Scat (Brackish) together is possible but requires caution due to mismatched flow preferences. Provide a spacious tank of at least 450 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Guppy

Poecilia reticulata

Scat (Brackish)

Scatophagus argus

🐠Family Group
Guppy
Livebearers
Scat (Brackish)
Oddballs
Temperament
Guppy
Peaceful (1/10)
Scat (Brackish)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Guppy
22–28°C
Scat (Brackish)
20–28°C
pH Range
✓ Compatible
Guppy
7–8.5
Scat (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Guppy
8–30
Scat (Brackish)
12–30
Water Type
✓ Compatible
Guppy
Brackish Tolerant
Scat (Brackish)
Brackish Required
Flow Preference
✗ No overlap
Guppy
Low
Scat (Brackish)
High
Min Tank Volume
Combined: 450 L
Guppy
38 L
Scat (Brackish)
450 L
Swimming Level
Shared: 1 zone
Guppy
TopMiddle
Scat (Brackish)
MiddleBottom
🏷️Behavior Tags
Guppy
Hyperactive / Fast SwimmerFry Predator
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper
Stocking calculator

Can your tank handle Guppy and Scat (Brackish)?

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.

Guppy
Scat (Brackish)
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Behaviour & Temperament

Guppy is a peaceful species (1/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Scat (Brackish) may occasionally assert dominance over Guppy.

Guppy 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.

To improve the chances of a peaceful coexistence in this community tank: Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

Water Parameters

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°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.

Tank Setup

To house Guppy and Scat (Brackish) together, plan for an aquarium of at least 450 litres with a minimum length of 150 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

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

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

Guppy prefers Low (Still Water) flow while Scat (Brackish) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Guppy and Scat (Brackish) need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Guppy and Scat (Brackish).

Frequently Asked Questions

Can Guppy and Scat (Brackish) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 450 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Guppy and Scat (Brackish) need?

A minimum of 450 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 Guppy and Scat (Brackish) together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Guppy or Scat (Brackish) aggressive?

Guppy is peaceful (1/10) and Scat (Brackish) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Guppy 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 Guppy's fins?

Scat (Brackish) is a known fin nipper. If Guppy 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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