rm
Passport
- Family
- Silver Dollar
- Grows to
- 15 cm (5.9")
- Lives
- 10+ years
- Temperament
- Peaceful
- Care
- Intermediate
- Swims
- Mid-water
- Keep
- In a group of 5 or more
- Water
- 24–28 °C (75–82 °F)
Brazil
Care requirements
i
On record for Silver Dollar: adult size, lifespan, minimum tank, temperature, ph, hardness, minimum group, diet, care level, swim level, tank length.
A figure that is not on record is left out rather than guessed. One marked Suggested comes from keeping knowledge rather than a page.
- Minimum tank 265 L / 70.0 US gal
- pH 6–7
- Hardness 4–15 dGH
- Diet herbivore
- Tank length 180 cm minimum
Care notes written from general aquarium knowledge, not from the cited sources.
About
Silver dollars are exactly what the name says: round, flat, metallic discs that catch the light as a shoal turns. They're relatives of the piranha with none of the reputation, and they're entirely peaceful toward other fish.
They are not peaceful toward plants. Silver dollars are dedicated herbivores and they will strip an aquascape to bare stems inside a week — not nibble it, demolish it. This is the single most important thing to know before buying them.
They're also nervous for their size. A startled shoal panics as a unit and can injure itself against the glass or the lid, so they want a calm room and a covered tank.
Tank setup
Give your silver dollars a big tank and a real group. They're deep-bodied shoaling fish that grow large, and a few of them in a small tank are permanently skittish.
Expect a bare or hardscape-only layout. Wood, rock and sand is the honest arrangement for this fish, and it suits their shape well.
Cover the tank securely and weight the lid. A panicking shoal hits the surface hard.
Keep the tank somewhere reasonably quiet. Sudden movement in the room sets them off.
Give them open swimming water through the middle of the tank, which is where they live.
Feeding
Silver dollars are herbivores and they need bulk plant matter, not a token vegetable once a week.
Feed vegetables daily: blanched spinach, courgette, peas, lettuce, kale, plus spirulina flake and vegetable pellets. Feeding them properly is also the only thing that slows the destruction of any plants in the tank.
Give them some protein occasionally, but it should be the minority of the diet.
Avoid: a protein-based diet, which suits their gut badly, and avoid assuming a well-fed silver dollar will leave your plants alone. It won't — it will just eat them more slowly.
Filtration and flow
Filter heavily. They're large, they eat constantly and a herbivore's waste output is substantial.
Give them moderate to good flow and strong oxygenation. They're active and they come from flowing South American rivers.
Change water generously. A big group of big fish loads a tank quickly.
With plants
Silver dollars eat plants. Comprehensively.
There is no reliable plant-safe option. Java fern and anubias are sometimes described as resistant and frequently get eaten anyway when the fish are hungry or simply curious.
Build the layout from wood and rock, and use artificial plants if you want greenery. This is one of the few tanks where that's the sensible answer.
Health
They're hardy and long-lived when properly housed.
Injuries from panic are the main risk. A fish with a damaged snout or scraped flank has usually hit the glass or the lid rather than being attacked.
Keep the tank covered and approach it calmly. Most silver dollar problems are behavioural consequences rather than diseases.
Breeding
They will spawn in a large, mature tank, scattering eggs among fine-leaved plants or over the substrate and taking no interest in them afterwards.
Softer, slightly acidic water and a rise in temperature are the usual triggers, mimicking the rains.
The eggs are non-adhesive and drift, and the adults will eat them. A separate tank with a mesh floor is what you need for numbers. Fry grow quickly and take baby brine shrimp early, moving onto vegetable foods sooner than most fry do.
Tank mates
Avoid6
- Common Pleco Common Pleco grows to 45 cm against Silver Dollar at 15 cm, big enough to eat it.
- Clown Killifish Silver Dollar is not safe with Clown Killifish: killifish and silver dollar are a bad pairing.
- Common Goldfish Common Goldfish is not safe with Silver Dollar: common goldfish and silver dollar are a bad pairing.
- Discus Silver Dollar and Discus do not mix: discus and silver dollar are a bad pairing.
- Fancy Goldfish Silver Dollar and Fancy Goldfish do not mix: fancy goldfish and silver dollar are a bad pairing.
Only with care60
- Chinese Algae Eater Chinese Algae Eater is aggressive and Silver Dollar is peaceful.
- Convict Cichlid Convict Cichlid is aggressive and Silver Dollar is peaceful.
- Jewel Cichlid Jewel Cichlid is aggressive and Silver Dollar is peaceful.
- Amano Shrimp Silver Dollar is a risk to Amano Shrimp: shrimp and yabbies and silver dollar are a pairing to watch.
- Assassin Snail Silver Dollar is a risk to Assassin Snail: silver dollar and snails are a pairing to watch.
No conflict is recorded with the other 38 species in the database, so nothing to flag. 4 species are not covered at all, so they could not be judged either way.