Silver Dollar
Metynnis hypsauchen
The Silver Dollar (Metynnis hypsauchen) is a peaceful fish that's easy to keep. Give it a tank of at least 250 litres (66 US gallons), water held at 75-82°F, and a pH of 6-7.5. Always keep a group of at least 5 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
South America
- South America
Regional colours match the stocking calculator's origin map.
Silver Dollar Tank Setup
A tank of at least 250 litres (66 US gallons) works well. Keep the water at 75-82°F with a pH around 6-7.5, and set up both cover and open swimming space where they spend most of their time (Mid). Always keep a group of at least 5 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour. They reach about 15 cm as adults, so don't be misled by the small juveniles sold in stores.
What Do Silver Dollars Eat?
They're grazers, so base their diet on algae, blanched vegetables, and spirulina-based foods rather than high-protein flake. A spotless tank with nothing to graze on leaves them thin and underfed.
Silver Dollar Tank Mates
Keep in groups of 5+. Herbivorous; will eat and destroy aquatic plants. Needs significant swimming space. The Silver Dollar is peaceful, which is the first thing to weigh up when you choose tank mates. It's a shoaling fish, so settle a group of 5 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Silver Dollars Good for Beginners?
Not a sensible first purchase. Get the tank cycled, keep easier fish stable for a year, then revisit if you still want the extra work this species demands.
Silver Dollar - frequently asked questions
What size tank do Silver Dollars need?
Silver Dollars need a tank of at least 250 litres (66 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Silver Dollars should I keep together?
Keep a group of at least 5. Silver Dollars are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Silver Dollars need?
Keep them at 75-82°F with a pH of 6-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Silver Dollars eat?
Silver Dollars are grazers. Base their diet on algae, blanched vegetables, and spirulina-based foods rather than high-protein flake. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Silver Dollars good for beginners?
Yes - Silver Dollars are a good beginner choice once the tank is fully cycled and you can keep a proper group. They are hardy but still need stable water and a school to feel secure.
Common mistakes with Silver Dollars
- Buying fewer than 5 - Silver Dollars need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
- Underestimating tank size - the minimum footprint is 250 litres (66 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Silver Dollars
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
