When it comes to choosing goldfish tank mates, it mostly comes down to size and temperature tolerances. Goldfish are relatively easy going fish; for the most part, there are always outliers. Here is a selection of what fish can live with goldfish:
Yes, your goldfish can be an only child. Most goldfish will be just fine on their own. They will get their interaction from their human family or other enrichment items in their tank. Some goldfish need to be solitary if they do not play well with others. Signs that your goldfish does not like having a roommate includes nipping at the other fish, chasing them, or pushing them into décor/tank walls. We see this more commonly with goldfish that are sole survivors from a disease outbreak and living on their own for months to years. When a new tank mate is added, please proceed with caution and keep a very close eye on the new kid.
The #1 tank mate for a goldfish is… another goldfish! Keep in mind that if you mix standard, long-body or comet goldfish with fancy varieties, the comets will beat the fancies to the food every time, causing stress and competition. Keep long-bodies with long-bodies and short-squashed bodies with other locomotionally-challenged fishes. Always keep in mind that you will need 20 gallons per goldfish and likely more as they grow, especially for long-body varieties.
These small, striped fishes do best if kept in a small school. Given that they are large enough to not fit in your goldfish’s mouth, zebrafish are peaceful and tolerant of lower water temperatures. Although they will eat the same foods as goldfish, they usually cannot fit the same size pellets in their mouths! You will likely need a second diet in order to keep these little fish happy.
No, we don’t mean the minnows in the pond or stream behind your house! Ornamental minnows have been specially bred in captivity for indoor living. Bringing wild fish into your home is NEVER a good idea. These species, such as the White Cloud Minnow, can look very similar to some tetra species, but have a better tolerance for colder water temperatures.
There are many species of snails that may wander into your fish tank. Usually riding along on live plants, these invertebrates can replicate very quickly if you happen upon a hermaphrodite species. Nerite snails, on the other hand, have distinct sexes, so you will need a male and a female to start making baby snails. It you can stick to just one snail or all one sex, snails make a good addition to goldfish tanks, since goldfish tend to be very messy fish.
Not Recommended Goldfish Tank Mates
Yes, we know goldfish can tolerate tropical climates. It will make them voraciously hungry and active. Just because you can mix goldfish in tropical tanks, does NOT mean you should. None of the following species are a correct answer to “what fish can live with goldfish.”
Betta fish are tropical fish, henceforth, they need warm water. Yes, your goldfish CAN tolerate warmer water, but they will be VERY hungry, making it hard for a slower-moving betta to get a fair share of the meal. And although they may be small, some bettas can be very aggressive and against a bigger tankmate, they don’t stand a chance.
For some reason, many hobbyists assume Plecos are temperate-water fishes. Sorry, but these guys like a little heat as well. They may not fit true “tropical” standards, but they need water in the high 70s for optimal health. NEVER put a Plecostomus in an outdoor pond! Many of these “mysteriously disappear,” AKA “die.”
Live-bearing fishes, in addition to needing heat, will constantly make food for your goldfish in the form of offspring. This high protein diet in a warmer environment will cause your goldfish to grow rapidly. Many goldfish will often then assume that the larger fish are also tasty. Don’t mix goldfish and guppies.