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Silver Dollar
Metynnis argenteus

Disc-shaped fish that look like shimmering silver coins. Peaceful but grow large and need a big tank. Will eat live aquarium plants — choose hardy species or use silk plants. Strong jumpers — keep a tight lid.

📏 Size: 15 cm
🐠 Tank: 55 gal
🌡️ Temp: 24–28°C
Easy

Quick Stats

Adult Size15 cm
Minimum Tank55 gal
Temperature24–28°C
pH Range6.0–7.5
Hardness (GH)4–15 dGH
DifficultyEasy
TemperamentPeaceful
DietHerbivore — plant matter, algae wafers, flakes, blanched vegetables
Schooling5+ required

Tank Setup

The Silver Dollar (Metynnis argenteus) requires a minimum tank size of 55 gal. For a species this size, a larger tank is always better — more water volume means more stable parameters and a healthier environment.

Water parameters should be maintained within the following ranges: temperature 24–28°C, pH 6.0–7.5, and hardness 4–15 dGH. These are relatively tolerant fish that adapt to a range of conditions.

Provide appropriate hiding places, a suitable substrate, and planted areas to match the natural behaviour of this species.

Tank Mates

Silver Dollar are peaceful fish. They work well in community tanks with similarly-sized peaceful species.

Compatible tank mates include: Larger Tetras, Corydoras, Bristlenose Pleco, Severum, Rainbowfish. Avoid housing with aggressive or much larger fish.

Schooling requirements: 5+ required. Keeping them in adequate numbers is essential for their wellbeing.

Diet & Feeding

Silver Dollar are Herbivore. Their diet should reflect their natural feeding habits.

Herbivore — plant matter, algae wafers, flakes, blanched vegetables

Feed small amounts 1–2 times daily. Only provide what the fish can consume within 2–3 minutes to prevent overfeeding and water quality issues.

Common Health Issues

Like all aquarium fish, Silver Dollar can be susceptible to common diseases including ich (white spot disease), fin rot, and bacterial infections. This species is generally hardy and disease-resistant when kept in good conditions.

Prevention is always better than treatment. Maintain stable water parameters, avoid overfeeding, quarantine new fish before adding them to the main tank, and perform regular water changes. A regular maintenance routine will prevent most health issues.

If disease does occur, isolate affected fish in a quarantine tank and treat appropriately. Always research medication compatibility before use — some treatments are toxic to invertebrates and scaleless fish.

Breeding

Breeding Silver Dollar is possible in the home aquarium.

Provide appropriate breeding conditions — caves or hiding places for egg-laying species. Condition breeding pairs with high-quality foods before attempting to spawn them.

Many Silver Dollar will breed readily without intervention. Be prepared to remove eggs or fry if you want to raise them — adult fish may eat their own young.

Frequently Asked Questions

What size tank does a Silver Dollar need?

A Silver Dollar needs a minimum tank size of 55 gal. However, larger is always better — more water volume means more stable water parameters and healthier fish.

Are Silver Dollar easy to keep?

Silver Dollar are rated as Easy difficulty. Beginners can keep them successfully with proper research and a cycled tank.

What do Silver Dollar eat?

Silver Dollar are Herbivore. Feed a varied diet including plant matter, algae wafers, flakes, blanched vegetables.

Can Silver Dollar live with other fish?

Silver Dollar are peaceful. Compatible tankmates include: Larger Tetras, Corydoras, Bristlenose Pleco, Severum, Rainbowfish. They work well in community tanks with similarly-sized peaceful fish.