The Silver Dollar (Metynnis hypsauchen) is a peaceful, fast-swimming freshwater fish known for its brilliant metallic silver coloration and distinctive round body shape. Closely related to piranhas but completely community-safe, Silver Dollars are popular for large aquariums where their schooling behavior creates an impressive display. These active fish thrive in groups and require spacious aquariums with strong filtration and plenty of swimming room. Quick Facts Scientific Name: Metynnis hypsauchen Common Name: Silver Dollar Adult Size: 6–8 inches Temperament: Peaceful Tank Size: 75 gallons minimum Temperature: 75–82°F pH: 6.0–7.5 Diet: Omnivore with strong herbivore tendencies Schooling Fish: Yes Why Choose Silver Dollars? ✔ Brilliant metallic silver coloration✔ Peaceful schooling fish✔ Excellent for large community aquariums✔ Active and entertaining swimmers✔ Great companion for Severums, Geophagus, and larger peaceful fish Aquarium Setup Silver Dollars are active, large-growing schooling fish that need plenty of open swimming space and a securely covered tank, as they can be skittish and may jump when startled. A spacious aquarium with strong filtration keeps these big-bodied fish healthy. Recommended setup: 75+ gallon aquarium (larger for groups) Open swimming areas with subdued lighting Driftwood, smooth rocks, and hardy or artificial plants (they nibble soft live plants) Strong filtration and regular water changes Soft, slightly acidic to neutral water Diet & Feeding Silver Dollars are omnivores with strong herbivore tendencies and a hearty appetite for plant matter. A varied, vegetable-rich diet keeps their silver coloration bright and their digestion healthy. High-quality vegetable flakes and pellets Blanched vegetables such as zucchini, spinach, and peas Spirulina and algae-based foods Occasional protein treats like bloodworms or brine shrimp Tank Mates Peaceful despite their size, Silver Dollars do best with other large, even-tempered community fish. Good companions include: Other Silver Dollars Bala Sharks Tinfoil Barbs Severums and other peaceful South American cichlids Large Plecos Larger Rainbowfish Avoid: Small tetras and nano fish (may be intimidated) Aggressive or fin-nipping species Delicate live-planted aquascapes (they will graze on soft plants) Schooling Behavior Silver Dollars are happiest in groups of five or more. Kept in a proper school they are calmer, bolder, and display their natural shimmering, synchronized swimming. Single or small numbers of fish tend to be shy and stressed. Frequently Asked Questions How big do Silver Dollars get?They typically reach about 6 to 8 inches as adults, so they need a spacious tank of at least 75 gallons. How many Silver Dollars should I keep together?Keep them in a school of at least five. Larger groups reduce stress and bring out their best, most active behavior. Are Silver Dollars peaceful?Yes. Despite being related to piranhas, they are gentle, peaceful schooling fish that get along well with other large, non-aggressive community species. Will Silver Dollars eat my plants?Likely yes. They are avid plant grazers, so hardy, tough-leaved plants or artificial plants are recommended. What do Silver Dollars eat?A vegetable-forward omnivore diet: veggie flakes/pellets, blanched greens, spirulina, and occasional protein treats. Available at Tropical Treasures Wyo Healthy Silver Dollars available for large freshwater aquariums and community fish displays.
