Silver Dollar Fish Care Guide: Size, Lifespan, Tank Size…

Have you ever thought of fish that look like your hard-earned money? If a large, shiny coin swimming around sounds right up your alley, then the Silver Dollar is for you. This popular aquarium fish is peaceful, hardy, and can get along with numerous other species. Not to mention being really easy on the eyes. Now if that weren’t enough, they’re also fabulously low-maintenance! 

The table below gives a quick overview of the Silver Dollar fish profile:

Profile AttributeValue
Care DifficultyEasy (but need plenty of space)
LifespanAround 10 years
DietOmnivorous but prefer plants and vegetation
Color(s)Silver (with occasional orange fin tips)
Maximum Size6 inches or 15 cm
Minimum Tank Size100 gallons (school of 5)
Tank SetupHeavily planted 
FamilyCharacidae (Serrasalmidae)
CompatibilityCommunity fish

Below is our Silver Dollar Fish care guide, continue reading to find out more about Tank Mates, Diet, Breeding and more.

Silver Dollar Fish Overview

There are a couple of fish species called Silver Dollar, but in the fishkeeping scene, the species most commonly referred to as Silver Dollar is Metynnis argenteus. This Silver Dollar fish  is a long-lived, low-maintenance aquarium fish that has the appearance of a, well, silver coin. They’re round, shiny, and flat on their sides which gives them a coin-like appearance. 

Native to South America, Silver Dollar fishes can be found in rivers with loads of plant life. They’re ravenous herbivores so this works well for them. In an aquarium, you won’t find a more ideal tank mate. Since they can get along with both small and larger-sized fishes, Silver Dollars are a popular community fish. As icing on the cake, they’re also incredibly hardy by nature and don’t have strict water requirements. There really is very  little to consider when keeping a Silver Dollar, making them good for aquarists of all types.


There’s no confusion as to where this fish gets its name. Silver Dollar fishes have a distinct silvery, coin-like appearance. They’re round, laterally flat, and their silver sheen sometimes have a blue-green tint to them depending on the light. 

The bodies of Silver Dollars have a striking shine, which becomes more transparent as it approaches their fin areas. Their dorsal fins are almost triangular in shape, while their caudal fins are semi-forked. 

Silver Dollar fish are sexually dimorphic, though the differences between the sexes might be subtle. Male Silver Dollars typically have a much longer anal fin than females. These fishes have a red-orange tint to their fins, but this feature is also more prominent in males. In fact, this coloration intensifies during breeding, and some males even develop two dark spots behind their pectoral fins. Female Silver Dollars on the other hand have no remarkable changes during breeding season. However, upon reaching adulthood, females are obviously larger and a bit more belly-full than their male counterparts. 

There are different kinds of Silver Dollar fish, such as the Red Hook Silver Dollar, and Spotted Silver Dollar. A species Metynnis hypsauchen even exists and is the most frequently confused with M. argenteus because of their similar appearance. The only notable difference is  the black spots present behind the eyes of M. hypsauchen

As for the others, Red Hooks have a noticeable blood red color to their anal fin, outlined in black. They also grow a bit larger than normal Silver Dollars, reaching up to 9 inches in captivity. Meanwhile, Spotted Silver Dollars are differentiated from other variations through the smattering of black spots all over its body. This type of Silver Dollar can reach around 6 inches in length. 


Silver Dollars are genetically predisposed to live long lives. They have an estimated lifespan of around 10 years, but some Silver Dollars even surpass this! So it should come as no surprise that with proper care, these fishes can grow to a very ripe old age. 

Average Size

When people buy juvenile Silver Dollars, they are only around a measly 2 inches. This seems like a manageable length, but you should know that they don’t stay this size for long. Upon adulthood, Silver Dollar fish can reach lengths of up to 6 inches! The males are a tad smaller than females, but needless to say, you’re going to need a substantial tank to house these fishes.

Silver Dollar Fish Care Advice

You’ll be very glad to know that caring for Silver Dollars is a total walk in the park (or tank). These aquatic pets have a hardy constitution able to withstand less than ideal water conditions, plus the occasional beginner mistake. Speaking of beginners, Silver Dollars are some of the most beginner-friendly fishes out there. Truly, the only indisputable requirement these guys have is a generous-sized tank. So once you’ve got their tank size down pat, you’re almost good to go.

Water Parameters

There is a widespread belief that Silver Dollars are one of the more difficult fishes to care for. This is far from the reality, because Silver Dollars are in fact good for newbies in the aquarium hobby. As usual, the best advice is to try and emulate the water conditions where these fish are from. 

Silver Dollars come from the rivers of South America and are used to soft and slightly acidic waters. In an aquarium, they can abide neutral or slightly basic pH levels since they are relatively adaptable. You shouldn’t rely too much on their tolerance however, because this may cause your Silver Dollars to get sick.

Water Parameters: 

  • Temperature: 75°F-82°F or 24°C-28°C
  • pH levels: 5.5-7.0
  • Hardness: 4-18 dGH (softer is better)
  • Water Flow: Moderate

All in all, Silver Dollars are not too fussy with their water requirements. What truly matters is that you keep them in warm, clean, well-oxygenated, and filtered water that has a moderate current. Don’t neglect regular water changes, as well as occasionally checking their parameters. 

Tank Size

Silver Dollars are no small fish, capable of growing up to 6 inches. To give them some wiggle room, allow at least 10 gallons per Silver Dollar. But since these not-so-little guys are also shoaling fish, they need their pals with them. Settle on at least 100 gallons for a happy school of five.

Inside Tank Setup

To set up both a beautiful and functional tank for your Silvery pets, we need to understand their needs. While generally placid, Silver Dollars also have skittish or nervous tendencies. When they are alone, or if your tank lacks the right structures, SIlver Dollars can become really uncomfortable and tense. Ease their worries by keeping them in schools as well as providing plenty of hiding places in your aquarium. 

Moreover, they appreciate plenty of vegetation similar to their natural habitats, so be generous with your plants. But keep in mind that SIlver Dollars are voracious herbivores called ‘Plant Piranhas’ for a reason. They will most likely devour your tank plants in a heartbeat. To avoid this, you can either choose vegetation they don’t find tasty, or opt for plastic plants instead. 

Once you’ve got your plants, set up your underwater world with dim lighting and an equally dark-colored gravel substrate. Doing so will not only please your Silver Dollars, but also create a beautiful contrast with them in your tank.

Potential Diseases

Thankfully, there are no rare, or hard-to-treat diseases for the average Silver Dollar (Phew!). Instead, they’re mainly vulnerable to the diseases common to ornamental and freshwater fishes, like Ich. As long as the disease hasn’t progressed to its advanced stages, there are plenty of medications available to treat them.

That being said, you can do your part and avoid your fish getting diseased in the first place. Indeed, most of these ailments are preventable with the proper care you get from this guide (wink*). Silver Dollars are naturally very hardy, so they don’t get sick easily. But perhaps because of that, many owners abuse this resilience and end up neglecting the welfare of their Silver Dollar. 

The best thing is to regularly monitor their water parameters, conduct frequent clean ups and water changes, as well as provide them with a nutritious and proper diet. Doing these seemingly little things can go a long way in ensuring your Silver Dollars live long and healthy lives. 

Diet & Food

Interestingly, Silver Dollars are actually from the same family as Piranhas, but their diets could not be more different. Silver Dollars are ravenous plant-eaters, but are able to sometimes eat meaty food like glassworms or shrimps. This is why many classify them as technically omnivorous, though they much prefer their veggies. 

Silver Dollar Fish Preferred food includes:

  • Vegetable flakes (spirulina)
  • Brine shrimp
  • Lettuce
  • watercress
  • Sliced cucumber
  • Spinach
  • squash
  • Peas
  • Fresh fruit

Feeding the Silver Dollar is an all together hassle-free experience. They’re fine with a twice a day feeding schedule, which can be easily done. At the end of the day be sure to clean up any leftover uneaten food from their tank. If you don’t, these food debris will go bad and pollute the water in your tank

Tip: If you have some time to spare, watch your Silver dollars during feeding time. Sometimes, fast swimming and more energetic fishes get the better of them and steal food meant for silver dollars. This can make your Silvery friends undernourished.

Silver Dollar Fish Tank Mates

Despite being from the same family, Silver Dollars are not the hot-tempered aggressors their Piranha relatives are. These shiny fish are instead known for being peace-loving and gentle souls. Because of that, choosing potential tank mates is no herculean task. There are countless critters perfect for life with the Silver Dollars. 

Silver Dollars are capable of hanging out harmoniously with smaller fish because they won’t eat them. They can also live in peace with larger fish because their substantial size doesn’t make them potential meals. They mostly stay in the upper levels of a tank, so bottom-feeders can also be an option if you’re looking for some variety. 

Tank Mates compatible with the Silver Dollar Fish:

Tip: Yes, Silver Dollars are even-tempered fellows who choose to live the vegan life. However, every once in a while they still fancy eating some meat. Avoid housing nano, or very small fish with the Silver Dollars;  they might just decide to have a cheat meal.

Silver Dollar Fish Breeding Behavior

Silver dollars are a prolific species, which is good news for those who want many of them in their tank. You may choose to put breeding pairs in a separate tank of around 40-50 gallons, but it’s not really required. 

About one year in, Silver Dollars develop subtle changes that will signify they are ready to mate. Male Silver Dollars get dark blotches on their bodies, while the orange tint to their fins become more prominent. They also become very active and prone to sparring with other males.

Meanwhile, female Silver Dollars are not as obvious, and remain mostly the same. However, both sexes are typically around four inches in length during their sexual maturity. 

Despite not really needing much help, some owners like to condition their Silver Dollars for breeding. They do this by separating sexually mature pairs into a different tank and feeding them a special diet. Setting the temperature and pH levels at a higher than normal range also sets off spawning.

Once the female is ready, then the mating dances start and don’t stop for days. These fishes are nothing if not enthusiastic when it comes to breeding, especially when their environment is to their liking. Silver Dollars are egg scatterers, and these eggs end up all over the tank. Some aquarists place marbles on the substrate floor for the eggs to fall through the spaces. There, the eggs are safe to develop until they hatch, and won’t be eaten. Once they hatch, the fry swim up through the spaces and can begin their life in the tank. 

Regrettably, Silver Dollars won’t be receiving any parenting awards any time soon, having no care for their young. So you’ll have to step up and feed their fry some plankton and flakes until they can care for themselves.

Temperament & Behavior

Unlike their Piranha relatives, Silver Dollars are generally peaceful shoaling fish, best kept in schools of at least 6. They love swimming around the tank with their buddies and would hardly stray from their pack. Silver Dollars typically leave other fish alone to their business, making them great community fish.

For instance, many decide to house much smaller fish with Silver Dollars because they are just that neighborly. However, It’s best to remember that they’re still omnivores who’ve just chosen the vegetarian way of life. So, a day may arise that your small fish will get eaten.

As a whole, Silver Dollars are amiable and chill fishes as long as they are with a big group. Without their posse, these fishes become skittish and will hide wherever they can find cover. Silver Dollars are also jumpers. When startled, they hop out so you should probably cover your tank up just to be safe. 


The Silver Dollar fish is a hobbyist favorite for a reason. They’re social, hardy, and low-maintenance fish good for both beginners and experienced fishkeepers. 

Caring for these stunning Silver Dollars is an absolute no-brainer (especially after reading this guide), and watching them swim around with their school is a real pleasure. They’re omnivores who prefer plants (a dream) and have many choices of tank mates. Truly, the only thing to worry about is their need for ample tank space, and after that it’s smooth sailing. 

There are also plenty of Silver Dollar varieties available to you, be it red Hooks, Spotteds or Tigers. In the end what matters is how well you take care of them for the rest of their long lives.

Note: Please consider the environment before printing this Silver Dollar Fish care sheet.

Leave a Comment