Goldfish are one of the most commonly kept aquarium fish in the whole world. They are native to East Asia, but several distinct breeds have been developed over time with varying sizes, body shapes, fin configuration, and colorations.
However, though this diversity has continually improved the general goldfish appeal, finding tank mates for this fish species has remained a challenge because of their quite messy nature and relatively large size.
Also, goldfish is one of the very few aquarium fish that prefer cooler water hence live without a heater in the fish tank.
On the flipside, very rarely will goldfish harm other fish, especially if they are not too small that they fit in the goldies mouth. Neither do males harm females during breeding.
Therefore, the only real threat that goldfish present to each other is competing for food and snacking on smaller tankmates.
That being said, there are a couple of freshwater aquarium fish that can be maintained with goldfish and this article will let you in on which ones to go for.
Can You Put Cleaner Fish With Goldfish?
As I mentioned before, a common challenge of keeping goldfish in a community aquarium is the excess ammonia they create with their excrements.
But that is not to say they will only live with other messy fish. Goldfish can also live with cleaner fish as long as the other fish is hardy and can adapt to a wide range of water chemistry.
The companions also need to be able to withstand a spike in ph and preferably, can survive in cold water.
In fact, it is best to put goldfish with cleaner fish because this reduces the amount of waste accumulating in your fish tank.
However, you will need to make sure you raise the fish in an aquarium that has a powerful filter, especially one with a reliable biological filtration media.
Moreover, if you perform regular water changes, clean your fish tank and vacuum your substrate properly, the aquarium should be safe for a host of freshwater aquarium species.
Ideally, change 10 percent of your fish tank water once a week if you have a new tank. And 25 percent every two weeks to a month in an established fish tank.
Having said that, to understand why bioload matters when choosing companions for your goldfish, you need to know the meaning of the term bioload.
Bioload is short for Biological Load which simply refers to all of the waste in the water column inside your aquarium.
This waste mostly come from poop, uneaten food, decomposing plant matter, fish breathing and other types of waste inside a fish tank.
That said, fish usually have different bioloads with most large-sized fish having a bigger load than small-sized fish.
However, this is also impacted by whether the fish is a meat eater or plant eater, how efficient the fish digestive system is and how much the fish eats or wastes.
Unfortunately, goldfish fall in the large, maybe even the gigantic bioload side. They are both heavy-messy eaters and produce a lot of waste which has an incredible amount of ammonia.
For instance, using goldfish and zebra danios as an example, a filter that can clean for 30 danios will not be able to keep up with the waste produced by 10 goldfish because they eat and poop a lot more.
Therefore, when choosing the fish to keep with goldfish, go for species with a considerably low bioload and can survive in a not-very-clean-tank for a reasonably long period.
The other hurdle while choosing goldfish companions is the size. Fancy goldfish can grow to between 7 and 8 inches and can easily get to a foot long. Whereas, common goldfish can reach 18 inches.
For this reason, you need a big tank (at least 40 gallons) whether keeping your goldfish with tankmates or singly.
Of course, when kept in a community tank, the fish will require more than 60-gallons for 2 to 4 fancy goldfish tanked with a school of small fish. Or a single common goldfish kept with the said school of small fish.
Plus you may need to move your goldfish once they max out the fish tank.
What Kind of Fish Can You Keep with Goldfish?
Now that you understand bioload and goldies average size, it is certain that the best kind of fish to keep with goldfish are small species that are generally peaceful and have a small bioload. Otherwise, you’ll have a hard time maintaining your aquarium water quality.
Also, goldfish do well in cold water, therefore, choose companion fish like Zebra Danios, that will survive in a heater-less aquarium.
Usually, goldfish prefer water that is between 65°F and 72°F, with a ph range in the community tank anywhere from 7.2 to 7.6. However, they can withstand variations better than other fish, so the ph should not constrain you too much.
Now, let’s switch gears and look at 7 good goldfish companions which include:
- Zebra Danios
- White Cloud Mountain Minnows
- Buenos Aires Tetras
- Gold Barbs
- Rosy Barbs
- Bloodfin Tetras
- Dojo (Weather) Loaches
- Minnows (Rosy Red)
Zebra danios are probably one of the best goldfish companion species because they like the same water temperature and are fast enough to outswim hungry goldfish for food.
Howbeit, fancy goldfish are also fairly fast and may starve out the danios occasionally.
Another advantage with zebra danios is they have a fairly low bioload compared to goldfish and also occupy lesser space. Which means you can have a school of danios and one or two small goldfish living in a 50 to 60-gallon fish tank.
White Cloud Mountain Minnows
White cloud minnows are another cold water fish species that make good companions for goldfish, they can even grow up together.
Howbeit, a large goldfish might eat young or small white clouds, but if they are too big to fit in the goldies mouth, they should be fine.
Therefore, tank white clouds with goldfish that are a little slower such that the minnows can out swim any aggressive tankmate.
Nonetheless, white cloud mountain minnow generally swim quite fast to be easily caught even by fancy goldfish.
Another advantage of white clouds is they are a small species with a reasonably low bioload. Thus cleaning your fish tank should not be too much of a problem as long as you have a filter that is adequate for a goldfish tank.
Buenos Aires Tetras
Buenos Aires tetras are a hardy tropical fish from South America that I highly recommend you consider for your goldfish tank.
These tetras are good community fish perfect even for beginner aquarists. And although they are generally tropical fish, they are capable of handling cooler water temperature.
The other advantage of Buenos Aires tetras over other goldfish companions is they grow to fairly large adult size (up to 2.8 inches) meaning they don’t run the risk of being snacked-out by large goldfish.
Unfortunately, the large size also means you can’t keep them in a small community aquarium given that goldfish are quite large as well.
However, the tetras are well behaved and have brilliant colors, so they will fit in most tropical and sub-tropical community tanks with or without goldfish.
Gold barbs can stand water temperatures down to about 64°F meaning they can live with goldfish. Besides, they also grow quite big, hence don’t run the risk of getting snacked-out.
However, when keeping goldfish with gold barbs, you will need to exert some caution because…well, barbs are still barbs, and if they are troubled, it might not end well.
For this reason, add these companions in a large fish tank where everyone is really mellow and has his own space.
If you set up your aquarium properly, you should have gold barbs and goldfish swimming together within 10 minutes of adding them in the fish tank.
Even so, you may notice the barbs hiding within the plants and decorations during the first few minutes of adding them in the tank.
Rosy barbs are another species from the barb family that can live with goldfish because they like the same type of water.
Same as gold barbs, they are also large enough hence won’t fit in a goldfish mouth assuming the goldies can even dare to attack the barbs.
That being said, rosy barbs are not aggressive and will live in most tropical and subtropical community aquariums either with goldfish or other freshwater fish.
However, keep in mind rosy barbs are schooling fish (same as most of the fish in this list) and need to be maintained in a group. Which means you will need s big aquarium.
Rosy barbs grow to between 4 and 6 inches long, and goldfish are not small fish either.
Although almost all tetras are tropical species that have to be maintained in a heated aquarium, bloodfin tetras, same as Buenos Aires tetras, can be kept in sub-tropical tanks with the temperature anywhere from 64°F to 83°F. So you could keep them with goldfish if you have a large fish tank.
Bloodfin tetras are a relatively large tetra species growing to 2.5 inches which means there is no way they’ll fit in a goldfish mouth unless when started in a tank with adult goldfish.
However, this also means you will need a bigger tank than you would if you were to keep your goldfish with small species like white clouds.
Dojo loaches, also called weather loaches make good goldfish companions especially because they both like cooler aquarium water (50°F to 72°F) and they also are bottom dwellers hence don’t conflict with the mid-level dwelling goldies.
However, these companions will only live together in a large aquarium because both species put out a lot of waste and grow quite big.
You will also need a large, powerful filter for the same reason.
Nonetheless, weather loaches are easy to care for and are good even for new fish keepers and a well-kept loach can live up to 10 years in a cold water aquarium.
That said, both goldfish and weather loaches can also live in a pond so you can maintain them in a fish tank until they max it out then move them into a pond.
Fortunately, moving goldfish from a tank to a pond involves following a similar process to that used to move fish from one tank to another. Therefore, it should not be too tasking.
(Rosy Red) Minnows
Apart from white cloud mountain minnows, a couple of other fish from the same family are acceptable goldfish companions. Howbeit, most are schooling species which that need to be kept in a group of preferably 5 to 6 individuals.
Therefore, to keep minnows with goldfish, you will require a large fish tank and a powerful filter that’ll vary in size depending on the minnow you choose to keep.
A common minnow likely to be found in a freshwater aquarium is the rosy-red variety which coincidentally, prefers cold water (50°F to 70°F ) same as goldfish.
However, the scenario where goldfish get large enough and devour smaller tankmates is quite probable in when they are combined with rosy red minnows. So, be careful with the matchup and should your goldfish get too big, consider placing it in a larger aquarium or pond.
Normally, rosy reds grow to an average size of 2 to 3 inches in males and 1 to 2 inches in length in females, meaning the extra bioload and need for space is not too restrictive.
A caveat for keeping rosy red minnow is although they are readily available even in rivers especially in the United States, they are usually very unhealthy when you buy them. This is because they are mostly feeder fish and its rare for hobbyists to keep them as pets.
So, you may want to place your minnows in a quarantine tank for a few weeks before adding them in the goldfish tank.
My Two Cents
As I have said from the start of this article, goldfish are tricky species to pair, and though every fish in the list above will live with your goldies, its good to consider the pros and cons of each fish individually.
Should you choose to keep your goldfish with minnows, the greatest risk you’ll run is your goldfish snacking on their tankmates because most minnows, including white clouds and rosy reds, are fairly tiny.
On the other hand, barbs are reasonably failproof, but they are quite large which is a disadvantage because you cannot maintain them in a small tank with goldfish.
Also, barbs are not entirely friendly and will retaliate should the goldfish trouble them, they are fin nippers as well.
Then the tetras, both Buenos Aires and Bloodfin, have fairly large bodies hence require a big aquarium. Plus any fish that like to hang around where goldfish swim is always an unwelcome guest because goldfish require a large swimming area.
Dojo loaches are perfect companions, but you will need a gigantic fish tank and a powerful filter to raise them with goldfish and still be able to keep the water quality safe.
So, in conclusion, try keeping goldfish alone before you consider adding them to a community tank.
Nonetheless, if you already have these fish, but you still want other species, the fish listed in this article are your best bet.
All the best, and have fun keeping goldfish