A large, peaceful schooling characin renowned for its laterally compressed, coin-like silver body. They are notorious herbivores that will devour almost any live plant in the aquarium. Highly skittish, they are known to dart rapidly when startled, requiring ample unobstructed swimming space and a tight-fitting lid.
Silver Dollar At a Glance
Silver Dollar Tank Requirements
Will Silver Dollar fit in your tank?
Care guides tell you what Silver Dollar needs, the next question is whether your tank can safely provide it. Test Silver Dollar against your tank size, maintenance needs, and the fish you already keep before you buy.
Silver Dollar Water Parameters
Silver Dollar Temperament & Compatibility
Silver Dollar Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard
The standard silver dollar seen in the trade. Must be kept in groups of 5 or more to prevent panic and stress. Best kept in a hardscape-only aquarium (driftwood and smooth rocks) as they will eat live plants down to the stems.
Same care requirements as the base species
Also known as: Common Silver Dollar
Silver Dollar Care Guide Summary
The Silver Dollar, scientifically known as Metynnis argenteus, belongs to the Characins family group. Adults reach a maximum size of approximately 15 cm and have a compressed body shape with a fast growth rate. Classified as peaceful, this species primarily occupies the mid-level and surface zones of the aquarium and produces a high level of biological waste.
To thrive, the Silver Dollar requires a freshwater only aquarium with a minimum volume of 280 litres and a tank length of at least 120 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 5.5–7.5 and a general hardness of 4–15 dGH. A moderate water flow is preferred.
The Silver Dollar is a rewarding species to keep, provided its core environmental needs are met. The Silver Dollar is typically available in one standard form.
Silver Dollar Habitat Setup
When setting up an aquarium for the Silver Dollar, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and surface zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels and driftwood, which can serve as both a hiding place and a dietary supplement. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper and live planted layouts may be difficult to maintain, as this species tends to uproot or consume vegetation.
Silver Dollar Compatibility Notes
Classified as peaceful, the Silver Dollar is a social species that requires the company of its own kind to thrive. Selecting tankmates that favour different water layers from the mid-level and surface zones can help reduce competition and territorial overlap.
Who Silver Dollar Is Actually For
Silver Dollar is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 5. It makes the most sense for a hobbyist who will actually build around its needs, especially driftwood.
The most common mistake is buying Silver Dollar for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.
Silver Dollar Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Silver Dollar.
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
180 Gallon Standard
350 Liter (120cm Deep)
Show 1 more tank size
Frequently Asked Questions About Silver Dollar
How big does Silver Dollar get?
Silver Dollar (Metynnis argenteus) typically reaches a maximum adult size of approximately 15 cm. They have a compressed body shape and a fast growth rate.
What tank size does Silver Dollar need?
A minimum aquarium volume of 280 litres and a tank length of at least 120 cm are recommended for Silver Dollar. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Silver Dollar need?
Silver Dollar thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 5.5 and 7.5, and a general hardness of 4–15 dGH. A moderate water flow is preferred.
Is Silver Dollar peaceful or aggressive?
Silver Dollar is classified as peaceful with an aggression score of 2 out of 10. They are generally well-suited to peaceful community tanks.
Can Silver Dollar live alone?
No, Silver Dollar should be kept in groups of at least 5 to reduce stress and encourage natural behaviour.
Does Silver Dollar have any special tank requirements?
Yes. Silver Dollar benefits from driftwood (digestion/hiding) and smooth gravel (sensitive barbels) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Silver Dollar need a lid on the tank?
Yes. Silver Dollar is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- April 28, 2026
- Last updated
- April 28, 2026
- Issues or corrections?
- Contact the editorial team
Top Tank Mates for Silver Dollar
These fish are strong compatibility matches for Silver Dollar based on water preferences, temperament, adult size, and tank behavior.
Trapdoor Snail
Cipangopaludina chinensis
Ideal Tank MatesRaspy River Stingray
Potamotrygon scobina
Ideal Tank MatesTandanus Catfish
Tandanus tandanus
Ideal Tank MatesGold Spot Pleco (L001 / L022)
Pterygoplichthys joselimaianus
Ideal Tank MatesApistogramma Marmor (Marbled Apisto)
Apistogramma erythrura
Ideal Tank MatesAlligator Pleco
Pterygoplichthys scrophus
Ideal Tank MatesPlants That Suit Silver Dollar
These plants pair well with Silver Dollar based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
Anubias Barteri
Anubias barteri
Balansae
Cryptocoryne crispatula
Belinda's Buce
Bucephalandra belindae
Bonsai Rotala
Rotala indica
Fish Similar to Silver Dollar
Plain Silver Dollar
Metynnis hypsauchen
A large, peaceful, schooling characin closely related to pacus and piranhas. Unlike their carnivorous cousins, Silver Dollars are primarily herbivorous and are notorious plant destroyers. They are highly active and easily startled, requiring large tanks with plenty of open swimming space, dim lighting or cover, and a tight-fitting lid to prevent jumping.
Pink Tailed Chalceus
Chalceus macrolepidotus
A large, incredibly active, and fast-swimming characin from South America known for its shimmering silver body and striking pink tail. They are primarily surface dwellers and are notorious jumpers, so a tight-fitting lid is absolutely mandatory. While generally peaceful with larger tankmates, they are predatory and will consume small fish. They must be kept either singly or in a shoal of 6+; small groups often result in severe squabbling.
White Cichlid
Vieja argentea
A striking, large Central American cichlid known for its brilliant silvery-white body speckled with black markings. Currently reclassified by many as Maskaheros argenteus, they are powerful, highly territorial fish. As herbivores/omnivores, they are notorious for shredding live plants and rearranging the tank substrate.
Silver Hatchetfish
Gasteropelecus sternicla
A uniquely shaped characin with a deep, keeled belly adapted for surface dwelling. Known as 'flying fish', they possess powerful pectoral fins used to leap from the water to catch insects or escape predators. A tight-fitting lid with absolutely no gaps is mandatory. They are peaceful schooling fish that require open surface swimming space and floating plants to feel secure.
Silver Prochilodus
Semaprochilodus taeniurus
A large, active riverine species famous for its striking striped tail and ability to consume massive amounts of algae. Commonly kept as a 'cleanup crew' in monster fish setups (with Arowanas or large Cichlids). They are peaceful towards other species but highly intolerant of their own kind unless kept in large shoals to disperse aggression.
Head and Tail Light Tetra
Hemigrammus ocellifer
A peaceful, schooling characin named for the reflective copper/gold spots on its head and the base of its tail. These 'lights' evolved to help the school stay together in the dark, tannin-stained waters of the Amazon basin. They are hardy, active, and make excellent community fish for planted aquariums.