Silver Dollar Fish 101: Care, Tank Mates, Size, & More

The silver dollar fish is a popular and unique freshwater fish that have been a staple inclusion in tanks for quite a while.

They have a very interesting and appealing appearance, but that’s not the only reason that makes them a great fish to own.

Silver dollar fish care is a fairly simple process that won’t take a ton of time, or cause you a bunch of headaches. These fish are relatively low-maintenance and will live for a long time if you hold up your end of the bargain.

They’re also great for community tanks. The list of possible silver dollar fish tank mates is quite long!

In this guide, we cover everything you need to know about silver dollar fish and how to take care of them. Then you can run out and get one for yourself!

Species Summary

The silver dollar fish (scientific name: Metynnis argenteus) can be found all throughout South America in rivers that contain heavy amounts of long vegetation. Their tall and thin build makes them perfect for navigating this environment and swimming between stems with ease.

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They eat mostly plants and are known for their ability to devour any plant in their path. In fact, one of their nicknames is the “plant piranha!” This is worth noting because it will impact how you decorate and fill your tank when it comes to plant life.

Silver dollar fish are also used to a variety of hiding spots in their natural habitat other than plants. Rocks and driftwood are scattered throughout the water they live in.

These are top dwelling fish which means they will spend most of their time in the upper half of your freshwater aquarium. Knowing this will be useful for when you map out potential tank mates later on.


The typical silver dollar fish lifespan is roughly ten years. However, it’s not that uncommon for them to exceed this by a year if they have good genetics and receive optimal care.

Because of their natural habitat, these are very hardy fish. However, this still means you can shorten their lifespan significantly if you don’t maintain the right tank and water conditions. As long as you take those things seriously you should expect to see them live quite long and happy lives!


The silver dollar fish looks just like, a silver dollar (shocking). Their bodies are tall and flat which gives them a rather circular appearance from the side.

The majority of their body is quite shiny but becomes more translucent when you get to their fins. Thie further accentuates their silver dollar similarities.

A large silver dollar fish swimming near the substrate

Their dorsal fins look a bit like a tilted equilateral triangle that starts at the highest point on their body. The front ridge of the dorsal fin is typically more opaque than the rest of it.

Their caudal fins are forked ever so slightly and are perfectly symmetrical. The silver caudal peduncle on these fish extends a bit into the caudal fin.

Silver dollar fish have slightly lumpy bodies. Starting at their head it’s a fairly clean triangle on top and bottom until the midpoint. Then where their dorsal fin starts is slants down before hitting a very slight bump. Meanwhile on the bottom, it flattens out before making a sharp turn up to the caudal fin.

Author Note: Silver dollar fish come from the same family as the piranha (characidae). When you compare their heads you can definitely see the similarities.

Types Of Silver Dollar Fish

There are a few types of silver dollar fish that you’ll see quite often. The standard silver color is by far the most popular, but they aren’t alone.

Red Hook Silver Dollar Fish

The red hook silver dollar fish has a very pronounced red anal fin that looks a lot like the rudder on a ship. The rest of their bodies look very similar to the classic silver dollar, but the coloration can sometimes be a bit more patchy.

Spotted Silver Dollar Fish

The spotted silver dollar fish is a neat variation that many aquarists seem to enjoy. They have a darker primary color on their body (more of a grey than anything else) and are covered in a series of dark brown spots.

Tiger Silver Dollar Fish

The tiger silver dollar fish is our personal favorite type. It is a very clean blue-silver with a series of large dark vertical stripes. This is a fun fish to watch swim!


The average silver dollar fish size is around 6 inches in length. There is the occasional report of them hitting 8 inches but that’s not to be expected.

These aren’t small fish which means you’ll have to plan your tank accordingly. Not only are they long, but they’re tall! The on;y space-saving featured about silver dollar fish is their width.

Silver Dollar Fish Care

Silver dollar fish care is not rocket science. These are hardy and durable fish that can thrive in a wide range of conditions.

Silver dollar fish

This gives you the luxury of not having to be paranoid about the absolute perfect tank conditions. With that being said, there are still a handful of things you’ll need to know.

Tank Size

A 75-gallon tank should be plenty for your silver dollar fish. This is assuming a 5 fish minimum for your tank. These are schooling fish that do much better in a group than alone, so we don’t recommend including less for the sake of saving space.

You’ll want to have a long tank for your adult silver dollar fish because they are active fish that like to swim. This will give them some distance to cover without feeling cramped.

Author Note: If you plan on exceeding 5 silver dollar fish in a tank, add 10-15 gallons per extra fish.

Water Parameters

Maintaining the right water parameters is crucial when it comes to silver dollar fish care. Despite their hardy nature, they can get into trouble if parameters shift too much.

  • Water temperature: 75°F to 82°F
  • pH levels: 5-7
  • Water hardness: 4-18 dGH – most experienced aquarists prefer somewhere in the 8 to 15 range.

What To Put In Their Tank

Silver dollar fish require a well-made habitat for enrichment and comfort. These fish are prone to high levels of stress if they spend time in an environment that they don’t understand or lacks what they need.

First, you’ll want to include a decent amount of plants that they don’t find tasty. This will allow them to feel at home without you having to add new plants every couple of days. If these fish like the plants in their tank, they will devour them in a matter of days!

Two great options are java moss and hornwort. These will provide them with a familiar and comfortable atmosphere, but not tempt their appetite.

An ample amount of driftwood and rocks will also be useful. Even though the silver dollar fish spend most of their time in the upper half of the tank, they will still appreciate having places to hide.

A gravel substrate is ideal since it will perfectly mimic the river beds in their natural habitat. Dark gravel is preferable.

Author Note: It’s smart to use a power head or two in order to achieve the ideal water flow. This will help enrich the water with an adequate amount of oxygen so your silver dollar fish can thrive.

Common Possible Diseases

There aren’t any species-specific diseases you have to worry about when comping up with a silver dollar fish care plan. These fish are very durable and hardy, which can make you breathe a little easier as an owner.

However, this doesn’t mean they can’t get sick. Silver dollar fish can get a lot of the same common illnesses that other freshwater fish get if you don’t take care of them (like ich).

The most effective way to avoid this is to take water quality, diet, and stress management very seriously. These all play a major role in the health of your fish, and keeping these in check will significantly reduce the risk of them falling ill.

Food & Diet

The diet of silver dollar fish can be a little confusing at first. While these fish are technically omnivores, they spend most of their time scarfing down plant life.

You have plenty of options when it comes to their preferred source of plant-based foods. Some of our favorites are:

  • Algae wafers
  • Plant-based flakes
  • Cucumbers
  • Peas
  • Lettuce
  • Other leafy greens
  • Seaweed

They will also appreciate the occasional treat of bloodworms and brine shrimp, but these should be fed to them quite rarely.

The standard feeding schedule for silver dollar fish is very convenient. These fish can do fine on a two times a day schedule which is way more convenient than 3-4 daily feeding sessions that some other species require.

Behavior & Temperament

Silver dollar fish are very pleasant fish to keep. They’re calm, not aggressive, and fairly active.

You’ll almost never see them show any kind of aggression toward each other or other fish in your tank. This makes them a great community fish that you don’t have to worry about.

Since they’re schooling fish you’ll always see them swimming with their buddies. It’s rare to catch one lurking out on their own since that will make them very shy and nervous.

A school of silver dollar fish

These fish will spend the majority of their time in the top half of your aquarium. This can make for some great pairings with other species that spend their time in the middle or bottom of tanks.

Author Note: Since the silver dollar fish is a top-dwelling creature you’ll want to make sure you have a sturdy tank hood. They’ve been known to jump!

Silver Dollar Fish Tank Mates & Compatibility

There are plenty of critters that make great silver dollar fish tank mates because of their gentle nature. For the most part, these fish simply want to mind their business and find plants to snack on!

Peaceful bottom-feeder fish are usually quite compatible with silver dollars since they spend most of their time in the upper half of the tank. This means not only will both species not want to fight, but they won’t even be near each other in the first place!

A few of our favorites in this category are bristlenose and clown plecos. Kuhli loaches and cory catfish also make good silver dollar fish tank mates.

There are a number of cichlids that also make great tank mates. The Oscar fish, red empress, and blue dolphin are all strong cichlid pairings.

Due to their size and durability, you have a lot of options when it comes to finding a tank mate for silver dollar fish. Just because you don’t see it on our list above doesn’t mean it isn’t compatible! If they have similar water requirements and aren’t aggressive, they can probably work!

Author Note: Fish that are super small might not work as silver dollar fish tank mates. Silver dollars are large and might mistake them for a snack! This means betta fish and neon tetras are not an option. 


Silver dollar fish breeding is pretty straightforward once you’ve identified a compatible mating pair.

You’ll need a breeder tank that’s somewhere in the 40 to 50-gallon range. The water temperature and pH levels should be on the higher end of their normal range to encourage the process.

Floating plants are a necessary inclusion in the breeder tank as well. This will mimic their natural environment and make the fish think they’re in an acceptable place to spawn.

The eggs that the female creates will fall to the substrate and the parents won’t be very involved with them after that point. This might seem a little odd since these are fish that prefer to be near the surface of the water, but it’s worked for them so far!

After a few days, the eggs will hatch and you’ll need to feed them foods like plankton and small flakes in order to assist their growth.

Tying It All Together

The silver dollar fish is one of our absolute favorite freshwater fish. They’re unique, fun to look at, peaceful, and very low-maintenance!

Caring for them is a fun experience that anyone can handle once they know what to do (which this guide has taken care of). Also because of their long lifespan, you’ll probably have these fish for quite a while as long as you provide them with a healthy tank to live in.

If you have any additional questions about silver dollar fish care that we didn’t cover in this guide please let us know. We want to make sure these resources are as useful as possible!

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