Goldfish are probably the most misunderstood aquarium fish out there. Even though it is the most popular aquarium fish in the world, few people have a clear understanding of these fish. Nothing demonstrates this more than the topic of tankmates. It immediately generates a reaction of ‘nothing can go with goldfish, they are coldwater’. This is wrong in many ways.
First, goldfish are not coldwater fish. They are eurythermal, which means they can thrive in a wide temperature range. They do at least as well in tropical temperatures as they do in room temperature. True coldwater fish have to be in cool water. This isn’t the case with goldfish at all.
There are a few things we need to get out of the way before we just list good options for tankmates for goldfish. First, in this article, I am talking about fancy goldfish. Although they are the exact same species, the differences between pond type goldfish and fancy goldfish are too numerous and significant to lump the two together. Second, the temperature you keep your goldfish tank at will make a massive difference in the options for tankmates. There are two main options for temperature, room temperature and tropical. Both have ranges. Tropical can be as low as about 76F. Room temperature can be in the 60s, or as high as 76F or so. If you keep your goldfish in tropical temperatures, your options for tankmates are much more numerous. The higher the temperature is, the higher the bioload. This means if you do keep your goldfish warmer, the water changes must be larger in order to allow for the increased bioload. Because room temperature can vary so much, you must check what temperature your tank actually runs at in order to properly select tankmates. It is also appropriate to point out that many of our ‘tropical’ fish really aren’t tropical. As you will see in the list below, many of the fish that are usually thought of as tropical not only can thrive in cooler, but some MUST be kept in cooler water.
It is also appropriate to point out that many of our ‘tropical’ fish really aren’t tropical. As you will see in the list below, many of the fish that are usually thought of as tropical not only can thrive in cooler water, but some MUST be kept in cooler water.
Once the temperature is determined, it is just a matter of choosing which fish are a good match. There are two factors to take into consideration: nippy fish and fish size. As is always the case, if something can fit inside the mouth of another, it will probably end up there. In addition, because most fancy goldfish are so big and slow, they can be an easy target for nippy fish. So the challenge is to find fish that will do well at whatever temperature your goldfish will be living in, won’t be eaten by the goldfish, and won’t nip at or chew on the goldfish.
I should point at that you will see many barbs listed below, even though we previously discussed how nippy fish should be avoided because goldfish make easy targets. This is because most barbs aren’t nippy. Tiger barbs are nippy, and unfortunately, this has set the reputation for the entire group. This leads many people to unnecessarily avoid all barbs. The reality is that most barbs are just like tetras or any other small community fish and not a problem at all.
Platy
64-77 F (18-25C)
3″ (7.6cm)
The platy is the best tankmate for goldfish, along with bristlenose plecoes. They love cooler water, stay small, and aren’t nippy like most livebearers. They come in tons of colors and patterns. They are herbivorous omnivores, just like goldfish. Although I am sure they exist, I have never once had issues with any platy being too nippy for goldfish. The most I have had is a quick nip or two, and then that’s it. And these incidents are so few and far between that I have completely forgotten the last one when I see it again. I have yet to have to actually remove a single platy for being too nippy. They are also large and bulky enough to not be eaten by goldfish.
Bristlenose Pleco
70-80F (21-26C)
5″ (12.7cm)
The bristlenose pleco is the other perfect tankmate for goldfish. I always keep them with goldfish. In general, plecoes are a horrible option to go with goldfish because they are so likely to chew on them. Bristlenose plecoes are a big and definite exception. Again, in all the years and different tanks I have kept them together with goldfish, not once has even one been a problem. I have never seen even one mark on a single goldfish. They are great at keeping algae under control, which makes them great to have in any tank.
Dojo Loach
41-77F (5-25C)
11″ (28cm)
Dojo loaches, also known as weather loaches, are a common tankmate for goldfish. They are a cool water fish. However, I have had issues with them chasing and stressing out goldfish, to the point of the goldfish having marks and even torn fins. I don’t think this is really the norm, I have seen the combination work enough times to know it isn’t likely, but I have chosen to no longer keep dojo loaches with my fancy goldfish. If you decide to try them, good luck, but keep an eye out for any signs of problems.
White Cloud Mountain Minnows
64-72F (18-22C)
1.25″ (3.1cm)
Although another classic fish to be listed as a great tankmate for goldfish, White Cloud Mountain minnows are small enough to be eaten. In general, goldfish are too slow to catch them, so their size doesn’t necessarily disqualify them as a tankmate for goldfish. However, every once in a while a goldfish will figure out how to catch them. I have no idea how they do this, but I have seen it happen multiple times where all of a sudden the minnows start disappearing. Once one of the goldfish learns how to catch them, they can make short work of all the minnows in the tank. If you decide to try White Cloud Mountain minnows, be aware that you could potentially lose them. If you have any minnows disappear, remove the others immediately for their own safety.
Zebra Danio
64-75F (18-24C)
1.5″ (3.8cm)
Zebra Danios are just like White Cloud Mountain minnows in that they are the same size and also like cooler water. They are at the same risk of being eaten if any of the goldfish learn how to catch them. Be aware that there are many varieties that are all the same species, including: zebra danio, gold danio (albino), leopard danio, blue danio, the long-finned versions of all of these, and all colors of Glofish danios.
Axolotl
72F MAXIMUM (22C MAXIMUM)
10″ (25cm)
I almost hesitate to put these on this list because although they can work, it has to be done in just the right way. Axolotls are in the same situation as goldfish, they will happily eat anything that fits in their mouth, but they are also an easy target for nippy fish. They are worse about eating fish because they are large and will easily grab fish at night while the fish are sleeping. They are worse about getting nipped because of their long gills. In addition to all this, axolotls are truly coldwater because they cannot be kept any warmer than about 72F. They will be severely stressed and die if kept too warm, unlike goldfish. However, the combination of axolotls and goldfish worked so well for me that it is worth discussing. The two work well together because the goldfish are too slow to nip the axolotls’ gills without being nipped themselves by the axolotls, but they are too big to be eaten by the axolotls. In my experience, the goldfish may get nipped once when straying too close to the axolotls, but quickly learn better. This may lead some people to believe the two should never be together if there is any risk of harm, but I subscribe to the idea that it is okay to let a kid fall down at the playground and learn rather than never letting them go to the playground. The key is that they have to be put together at the right size. If the goldfish are too big, they could end up doing harm to the axolotls, but if the axolotls are too big they may tear up or even eat the goldfish. If you choose to try axolotls, do not keep any other fish in the tank at all, just goldfish. Although goldfish are fine with a lot of other fish, the axolotls are not. For a complete guide on axolotls, please read the Axolotl Care Guide.
Hillstream Loach
61-75F (16-24C)
2.25″ (5.5cm)
The hillstream loach is a very unique fish that stays nice and small and loves cool water. This is one that is not a good option if your goldfish tank will be a little warm, they max out at about 75F, so don’t push them. If your tank will stay cool these are a great option. They look like miniature stingrays, are schooling, and love strong flow. In addition to the normal variety, there is also the reticulated hillstream loach with an even bolder pattern (and usually priced to match). Although on the smaller end, these fish still make great options for fancy goldfish and are at very low risk of any goldfish making a meal out of them.
Checkerboard Barb
68-75F (20-24C)
2″ (5cm)
Checkerboard barbs are one of those unfortunate species that always seem to look bad in the stores. They are usually nothing more than an easily overlooked gray fish with black blotches. However, in as little as a few weeks in a good tank, they can settle in well and have outstanding colors. The gray takes on a blue/purple hue with beautiful irridescence, made even better by the boldly contrasting red fins. If you like nice looking fish that offer more than just bright colors, this is truly a diamond in the rough.
Scissortail Rasbora
73-77F (23-25C)
5″ (13cm)
Their colors and patterns are more subtle, but their size, schooling behavior, and tendency to stay in the upper areas of the tank make scissortail rasboras an attractive addition. They are unassuming, hardy, active, and large enough to be a great accent to the goldfish.
Gold Barb
64-75F (18-24C)
3″ (7.6cm)
Gold barbs aren’t as easy to overlook as some fish, but still aren’t as popular as they should be. They are boldly colored with a brilliant yellow base with striking green blotches and a red tail. They are also relatively large at 3″, but aren’t too heavy or stocky.
Rosy Barb
64-72F (18-22C)
5.5″ (14cm)
Coming in multiple colors and even long-finned varieties, rosy barbs are an active, brightly colored, attractive addition. These fish are confident, hardy, and will surely bring a lot of activity to the tank. Many of the color forms look as if they have orange or red metal foil for scales. They are truly beautiful fish.
Giant Danio
72-75F (22-24C)
5.5″ (14cm)
These top dwellers can be an excellent balance to goldfish and many of the other fish on this tank that tend to spend most of their time near the bottom. They are active, relatively large, and have a great combination of bold pattern, yet modest colors. Because of their size and relatively large mouth, they aren’t a good option if you will have small tankmates such as zebra danios or White Cloud Mountain minnows as they will get eaten.
Bloodfin Tetra
64-82F (18-28C)
2.25″ (5.5cm)
Bloodfin tetras are a great option for a community tank, including with fancy goldfish. Their simply gray bodies make their bright red fins stand out even more, no matter what background they are up against. They are hardy and active additions to a goldfish tank.
Black Skirt Tetra
68-79F (20-26C)
3″ (7.5cm)
These are large, peaceful tetras that come in multiple color morphs including white skirt tetra, which is also what was used to produce the Glofish tetras. These are large enough to be a great eye catcher and have no chance of being eaten by the goldfish. They are more laid back than many of the other smaller fish on this list, so if you want something a little more subdued, they are a great option.
Summary
There are many more potential options than just what are listed above, but any tankmates for fancy goldfish need to be selected very carefully. They must be large enough to not be eaten (or very active), not nippy, and thrive in the temperature your goldfish tank will be kept at.