The goldfish, a classic and much-loved kind of fish. They are cute, beautiful, smart, and equally popular among kids and adults. Though most people assume that goldfish can’t be kept with other species of fish, that’s not true. Fortunately there are other peaceful, cold-blooded fishes and invertebrates can be your goldfish’s companions in your aquarium.
It is, however, important to consider the specific compatibility needs of your little goldfish if you want your fish to thrive appropriately. While you should pick a tank mate that likes similar tank conditions, there are other things that you definitely need to keep in mind as well.
Make your way through this guide to learn all about the tips and recommendations of goldfish tank mates. Let’s get started!
Types of Goldfish
Before you start looking for a tank mate for your fish, you first need to identify the type of goldfish you have. For that, you need to check out its features like the body shape, tail, and other special traits. Based on their body shape and design, goldfish are basically divided into two major types. This is an important factor to consider while selecting a companion.
The two types of goldfish are:
Hearty Single-Tail Goldfish
The hearty single-tail goldfish features a slim, streamlined body with a single tail. Unfortunately, they do not have a lot of options for companions, as they tend to get very large and eventually outgrow their tank mates. The best option for this type of goldfish is another single-tailed goldfish or species that can live in a pond.
The fancy goldfish, as the name suggests, has beautiful features like bubble eyes and double tails. However, their round bodies slow them down, making it difficult for them to maneuver in the water, unlike the hearty goldfish. Fancy goldfish have better compatibility with most tropical fish if chosen wisely.
What to Look For in a Goldfish Tank Mates?
While goldfish are playful on their own and don’t really need a companion, they can thrive better in a multi-species environment. However, they are not as easy to take care of as some of you might think. The trickiest part is they have some specific requirements that determine their compatibility with other species. This is why you need to keep their uniqueness in mind, and consider certain traits accordingly for potential tank mates.
Here’s a list of the most important of their requirements.
For starters, goldfish are cool water fish, and they prefer a temperature range from 65° F to 75° F. So, you need to choose a tank mate whose ideal temperature range overlaps with your goldfish.
The majority of the species in the aquarium trade come from tropical areas across the globe. They require warm temperatures ranging between 75° F and 85° F, which is too hot for goldfish to live in. And, keeping these tropical fish in cooler water can lead to stress and illness over time. Some common aquarium fish, including angelfish, gouramis, and bettas, must be kept at a temperature around 80°F in order for them to live comfortably.
Goldfish also require periodic cold spells, unlike tropical fish, to shed off their excess fat. This factor makes it quite difficult to find ideal goldfish tank mates.
Goldfish are omnivores, and they are ALWAYS hungry. They are voracious eaters and will eat any fish that is small enough to swallow.
This isn’t too big a deal when your goldfish is small. However, as they grow larger, chances for tank mates looking like a potential snack get higher. Goldfish are not mean or aggressive, but they will take a bite out of any tank mate that can fit into their mouths, no matter how long they have lived together.
Invertebrates and smaller fish are their usual diet, and goldfish are happy to eat them. Your goldfish tank mates must be compatible and match the size of your goldfish. This will avoid the risk of your other fish being viewed as a snack.
When choosing a tank mate, a medium-sized fish around 3-4 inches long is ideal. If you put a smaller fish in the tank, it won’t be long until it is eaten up. You see, goldfish are not aggressive; it is rather an issue of mistaken identity!
Shrimps as a tank mate for goldfish is not a good idea unless they are large enough to not fit in the fish’s mouth. Snails are their potential snacks, so you should avoid choosing Nerite snails or other snail species with pointed cone-shaped shells as tank mates. Swallowing such snails can hurt or kill your goldfish.
Minnows and other small fishes can live with goldfish until the latter is big enough to eat them. Goldfish are also tempted to nibble at long fins, so it’s better to get a tank mate that matches the size of your goldfish and has short fins.
Matching Swimming Speed & Agility
The best tank mate for your goldfish is one with similar swimming speed and agility. You must match the activity levels of tank mates to prevent stress and avoid injuries. Depending on their type, goldfish have varying swimming speeds. For instance, a comet goldfish roams around at higher speeds, so you must choose a fast swimmer as a tank mate for it. This will keep the tank mate from being bullied or outcompeted for food.
Meanwhile, fancy goldfish have to deal with the opposite. They have bulbous bodies with flowing double fins, which makes them relatively slow swimmers. Pairing them with a fast swimmer is just asking for trouble. This will make the goldfish vulnerable as the tank mate might nip their fins, leading to severe infections and injuries. Plus, the tank mate might eat all their food.
If you want to keep small fishes in your aquarium with goldfish, make sure they are fast swimmers so they can easily out-swim a hungry goldfish.
Despite their habit of swallowing smaller mates, goldfish are thought to be very peaceful. They don’t usually act aggressively or nip fins. Similarly, they don’t establish territories or defend them from tank mates.
Avoid keeping goldfish with aggressive or semi-aggressive tank mates like Tiger Barbs or African cichlids, who are known for fin nipping. It is also suggested to keep goldfish in pairs or groups, as they are quite social among their species. They tend to get lonely and bored if kept on their own, plus they really can’t stand up to bullying by other tank mates, which can result in stress.
So the tank mate you choose for goldfish should be peaceful. An aggressive tank mate will put your goldfish at risk of being stressed, beaten up, or even killed.
Landscape and Terrain Needs
Before pairing your goldfish with a tank mate, make sure to examine the plant types, ideal substrate, and other things that could possibly affect the landscape and terrain. Goldfish will eat small gravel or sand, making them ill from the substrate. This is why it is ideal to keep mid-sized to large gravel in the aquarium.
It is also important to get a large aquarium for the goldfish and tank mates to live in. Goldfish tend to swim around a lot, thus requiring plenty of space to move.
Benefits of having a tank mate for Goldfish
Goldfish are playful and can live on their own. However, adding a tank mate can bring several benefits, including:
Getting a compatible tank mate for your goldfish will provide them with added entertainment and companionship. It will not only fill up the aquarium, but will also increase the activity level in it. All you need to do is find the right tank mate for your goldfish.
A goldfish-only aquarium can be boring. Putting some tank mates in the aquarium will add variety and color to it, improving the aesthetic and visual appeal.
Ideal Goldfish Tank Mates
With all the basics established, let’s look at some of the best tank mates for your goldfish.
For goldfish, there’s no better companion than another goldfish. Since they are very social, goldfish love living among other goldfish. They are rarely aggressive and make for an inexpensive addition to your aquarium. Common goldfish are available in a range of colors and patterns.
However, you need to consider the swimming speed and agility here. Comet goldfish can’t be paired with fancy goldfish, as the former is a fast swimmer and will gobble up all the food quickly.
Rosy barbs are colorful freshwater fish with a gorgeous reddish-pink hue. They are peaceful and do well in slightly cooler environments, making them a suitable candidate for a tank mate. However, there must be a group of five Rosy Barb in the tank. Without that support system, they tend to become overly aggressive or territorial.
While these fish can be nippy, they are less likely to bother your goldfish if kept in a large school. If you put them with your goldfish, they will just interact with each other and leave the goldfish alone. Plus, their large size prevents them from becoming a snack for goldfish. However, they are fast swimmers, so you will have to ensure that you give enough food to your goldfish.
Platies are colorful and grow to around 1-3 inches long. While they are generally considered tropical fish, platies can easily thrive under 70° F. Adult platies have thick bodies with a short fan-shaped tail. They come in different patterns and colors, including gold, orange, green, red, white, and even black.
Platy fish are livebearers. This means they give birth to young ones instead of laying eggs. There is a good chance that your goldfish will eat the recently hatched fish though, unless they are moved to a separate tank.
While they are fast swimmers, it is recommended that you provide some hiding spaces like artificial plants. This will help give them refuge from the goldfish.
Giant Danio is probably the best minnow to keep with your goldfish. They grow up to four inches, so your goldfish won’t be able to eat it. They are similar to their cousin, zebra danios, but with distinct coloration that adds visual appeal to the tank.
They are schooling fish and enjoy swimming in a current, thereby leaving space for your goldfish. Since they are very fast, they are not ideal for keeping with a fancy goldfish as they will outcompete the latter for food. However, they can thrive with comet goldfish and other fast swimmers.
These black and silver-colored fish are tiny and fast and have similar temperature requirements as goldfish. Since they are small, they can be a potential snack for goldfish; however, their agility helps them out-swim goldfish most of the time.
These fish feature a slim body with yellow and blue stripes running from the nose to the tail. They like to school and usually stick together, making it hard for the goldfish to capture them. It is still better to put some artificial plants in the tank, so the danios always have a place to hide.
White Cloud Mountain Minnow
White cloud mountain minnow is cold-water fish, which means they can thrive in the same environment as your goldfish. They are small and usually 1.5 inches long. Their small size can put them at risk of being eaten, but if you put them in a large group of 5 to 10 it can work out well. Plus, their speed helps in keeping them safe from hungry goldfish.
These minnows are very pretty, with slim bodies covered with silver-green scales. They have a bright pink to red tint to their fins and have an iridescent stripe running from the nose to the tail. This way, they add a nice color contrast to the goldfish in the aquarium.
You may need to feed them a different diet, considering their tiny mouths as compared to your goldfish.
Dojo Loach or Weather loach are great goldfish tank mates. They are bottom feeders and have slim, sausage-like bodies and tiny fins. They use their body to swim like a serpent. This fish isn’t aggressive at all as it prefers hiding away and eating rather than getting into a fight.
The Dojo Loach likes to burrow in the substrate and watch other fish be more active above them. They are great at ensuring that the substrate has no uneaten food in it. This fish generally hides during the day and comes out at night in search of food.
However, the ability to climb makes these fish quite challenging to keep. It is best to have a secure lid, so the fish don’t squeeze through a gap.
If you are looking for an alternative to fish as a tank mate for your goldfish, cherry shrimps are a good option. These active invertebrates are quite popular in the aquarium trade. Their vibrant red body not only makes them easy to spot, but they also add a unique color to the tank.
They grow up to 1.5 inches long and occupy the bottom of the water column. You need to be careful with them though, as they can quickly become food for larger goldfish. One trick to protect them is to provide plenty of hiding places at the bottom of the tank. Add sandy substrates and many plastic plants of varying heights, and the shrimp will be safe.
With a distinct look, the Hillstream Loach is a shy scavenger. With their ability to thrive in cool water they make for excellent tank mates with single-tail or fancy goldfish. Adults are usually 3 inches long and prefer to live in large aquariums in order to set up territories.
This fish has a streamlined body and a flat belly with horizontal ventral fins. Since they are bottom dwellers, they are likely to stay out of the sight of goldfish. They spend their day clinging to glass, plants, and rocks while feeding on algae. This way, they don’t even have to compete with your fish for food.
Native to South America, Hoplo Catfish can do well in lower temperatures due to their overall hardiness. These fish have an attractive appearance with distinct markings. They are peaceful in nature and can easily adapt to a wide range of environments. They generally feed during the day, so you will see a lot of activity in the aquarium during that time.
Mystery snails, or apple snails, aren’t generally considered tank mates. However, they add some fun personality to the tank and are super cute to look at. Mystery snails are relatively bigger than other freshwater snails and come in a wide range of colors such as brown, black, ivory, albino, and golden.
They adapt to a wide range of water conditions and will get along with your goldfish very well. Since they are omnivore scavengers, they eat up organic waste, keeping the tank clean, which is a huge plus. Their shell provides them protection from hungry goldfish, and once your goldfish knows they can’t eat the snail they will leave it alone.
Species You Shouldn’t Consider as a Tank Mate for Goldfish
While we have looked at some options that prove to be an excellent tank mate for your goldfish, some species that you should definitely not pair with your goldfish include:
Most tetras are aggressive and fin-nippers. They become an aggressive nightmare in the presence of long-tailed fish. Their territorial tendencies also become a problem for the innocent goldfish, as they can’t protect themselves from attackers.
- Common plecos
Common plecos are not suitable goldfish tank mates as they tend to suck the slime off the goldfish. This can put your goldfish at risk of serious infection.
Bettas are another aggressive species that likes to attack goldfish. They also need warmer water temperatures to thrive.
Mollies are tropical fish, which means they have strict warm temperature requirements. Plus, they are likely to attack your goldfish, so it’s better to steer clear of this fish.
Can goldfish mate with other fish?
Yes, goldfish can mate with a fish outside of their own species if the tank conditions are right. According to new research, female goldfish will mate with other fish if they aren’t choosy and the male coloring is attractive enough.
Can goldfish live in a tank with a heater?
Goldfish are cold-water fish, but they might be able to be kept in a heated tank, depending on where you live. The optimum temperature for them to thrive ranges from 65° F to 75°F, so you may require a heater to combat temperature changes if it is colder than that generally. A heater will ensure that the temperature stays steady in the tank and the goldfish can live comfortably.
Can you put guppies with goldfish?
No, it’s not best to keep guppies with goldfish in the same tank as both of them prefer different temperatures. Guppies are also fin-nippers and like to live in warm temperatures. Your goldfish will, therefore, get hurt if kept with guppies.
Can tetras live with goldfish?
Most types of tetras are quite aggressive, which is why putting them with your goldfish in the same aquarium is not a good idea. They are likely to attack your fish and nip its fins, leading to injuries.
Which is the best tank mate for goldfish?
The choice of the best tank mate for goldfish depends on various factors, including temperature, diet, size, aggression, much more. The perfect tank mate for your goldfish is one with similar temperature requirements, swimming speed, and compatible size.
What kind of tank do goldfish need?
As a rule of thumb, a single fancy goldfish needs at least a 20-gallon tank. Other species like common goldfish and comet goldfish require at least a 30-gallon tank for one fish.
One gallon of water for every 2 inches of goldfish is another good rule to follow. Also, try to pick a rectangular tank rather than novelty or tall tanks.
Your favorite goldfish needs the best companion, which is why you must pick one only after careful research. An ideal tank mate is one that’s peaceful and can cohabitate in similar temperature conditions, is reasonably sized, and of course, is not overly active.
We hope that you now know how to find the ideal tank mate for your goldfish!
Hi, my name is Adam and I’m an aquarium enthusiast! I didn’t discover the joys of being an ‘aquarium fanatic’ (as some of my friends call me!) until I was in my 20’s. When I first started out I found it difficult to find all the information I needed so I started this website to compile all the useful information I can think of. Enjoy!