Can Plain Silver Dollar and Scat (Brackish) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 2, 2026
Not Recommended

Plain Silver Dollar and Scat (Brackish) are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Plain Silver Dollar

Metynnis hypsauchen

Scat (Brackish)

Scatophagus argus

🐠Family Group
Plain Silver Dollar
Characins
Scat (Brackish)
Oddballs
Temperament
Plain Silver Dollar
Peaceful (2/10)
Scat (Brackish)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Plain Silver Dollar
24–28°C
Scat (Brackish)
20–28°C
pH Range
✓ Compatible
Plain Silver Dollar
6–7.5
Scat (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Plain Silver Dollar
4–15
Scat (Brackish)
12–30
Water Type
✗ No overlap
Plain Silver Dollar
Freshwater Only
Scat (Brackish)
Brackish Required
Flow Preference
✓ Compatible
Plain Silver Dollar
Moderate
Scat (Brackish)
High
Min Tank Volume
Combined: 489 L
Plain Silver Dollar
280 L
Scat (Brackish)
450 L
Swimming Level
Shared: 1 zone
Plain Silver Dollar
MiddleTop
Scat (Brackish)
MiddleBottom
🏷️Behavior Tags
Plain Silver Dollar
Hyperactive / Fast SwimmerPlant DestroyerJumper (Lid Required)Shy / Slow Moving (Easily Stressed)
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper
Stocking calculator

Can your tank handle Plain Silver Dollar 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.

Plain Silver Dollar
Scat (Brackish)
Test both in my tank

Behaviour & Temperament

Plain Silver Dollar is a peaceful species (2/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Scat (Brackish) may occasionally assert dominance over Plain Silver Dollar.

Plain Silver Dollar 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Plain Silver Dollar is a known jumper, so a tight-fitting lid is essential.

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

For general hardness, the shared comfort zone is 12–15 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Plain Silver Dollar and Scat (Brackish) together, plan for an aquarium of at least 489 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.

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: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Sand (Sifters), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

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

Why This Pairing Usually Fails in Practice

Plain Silver Dollar and Scat (Brackish) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Plain Silver Dollar and Scat (Brackish).

Diet & Feeding

Feeding time deserves special attention with this pairing. Scat (Brackish) is an aggressive eater that may prevent Plain Silver Dollar from getting enough food.

Because Scat (Brackish) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Plain Silver Dollar receives an adequate share.

Frequently Asked Questions

Can Plain Silver Dollar and Scat (Brackish) live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Plain Silver Dollar and Scat (Brackish) need?

A minimum of 489 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 Plain Silver Dollar 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 Plain Silver Dollar or Scat (Brackish) aggressive?

Plain Silver Dollar is peaceful (2/10) and Scat (Brackish) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Plain Silver Dollar and Scat (Brackish) need?

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

Will Scat (Brackish) nip Plain Silver Dollar's fins?

Scat (Brackish) is a known fin nipper. If Plain Silver Dollar 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.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 2, 2026
Last updated
May 2, 2026
Issues or corrections?
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