Did you know your goldfish can die because of its tankmates? Yes, that can happen.
We understand the urge to add a little variety to your aquarium. However, if you don't select the tankmates for your goldfish carefully, you could end up doing more harm than good.
It doesn't help that choosing tankmates for a goldfish is a lot harder than choosing tankmates for other kinds of fish.
However, if you get it right, your goldfish will be happier, healthier, and safer. You don't have to worry about waking up one morning to find it dead in your aquarium.
So, what are the kinds of fish that can live with goldfish? Check out this guide for everything you need to know about getting companions for your goldfish.
You'll learn about the factors that determine good goldfish tankmates, the best tankmates for goldfish, and lots more.
Let's begin, shall we?
Factors to Consider in Selecting Goldfish Tankmates
The diet of fishes in your tank should be similar as they will also come in contact with the food you give others. Fishes that need "meaty" diets that are different from what a goldfish will take are not suitable companions. There is a chance that your goldfish will get too much protein in its system and experience constipation.
You need to choose fish that can live in the same conditions or at least conditions that overlap your goldfish. A lot of tropical fishes need warm temperatures that are too hot for a goldfish. Goldfish thrive in cooler temperatures of about 60 - 74⁰F and will do well at room temperature without heaters’ need. (ref. 1)
Agility and Swimming Speed
Goldfish are generally fast swimmers, so if you put them with smaller and slower fishes, there might be some complications. If the smaller fishes cannot outswim the goldfish, they will lose out on food and be unable to survive in the tank.
Fancy goldfish are slower than other species, so they have the opposite problem. The best option is to ensure both kinds of fish have similar speed and agility levels, so none of them starves in the aquarium.
Size and Fin Length
Goldfishes are always hungry and will pretty much eat anything in the tank that can fit into their mouth, including other fishes. Avoid fish that are small in size and go for those that are at least 3 inches and can't fit in the goldfish's mouth.
So, shrimps, snails, and minnows are a terrible idea to keep in the same tank as your goldfish. Fishes with long fins too can become a problem because goldfish like to nibble on their fins.
Territoriality and Aggression
Goldfish are generally peaceful fishes that don't set territories or protect areas from other fishes. You should avoid aggressive tankmates and only choose from the friendly ones.
If a fish tries to bully them, there isn't many goldfishes can do to defend themselves. Try to avoid territorial fishes that could attack your goldfish as that could end up killing them.
Top 7 Best Tankmates For Your Goldfish
In no particular order, here are the seven best tankmates you could ever get your goldfish.
1. Dojo Loach/Weather Loach
The dojo loach is a bottom feeder that would be a great addition to your goldfish tank. Dojo loaches are sensitive to barometric pressure changes and tend to get agitated when a storm builds up.
You need at least 75 gallons of water to keep a three-fish group. They are generally peaceful and are known to be omnivores that need temperature ranges of 65o-75oF.
One thing to note is that if you decide to add this fish into your tank, its ability to climb. You need to get secure lids with vented coverings to cover every opening, or you might have a hard time keeping track of them.
They can quickly grow to 1 foot, and because of their nature, you will need regular filtration as well as a strict maintenance schedule.
What to watch out for:
Putting them together with goldfishes will put a strain on your filter, so make sure it can handle it before adding them to the aquarium.
2. White Cloud Mountain Minnows
White cloud mountain minnows are small fishes as they grow to a length of about 1.5 inches. They are known for their speed, which keeps them safe from goldfish trying to eat them.
You need a tank size of at least 10 gallons to keep them. Even though they are also omnivores, you might have to feed them a different diet as their mouths are tiny compared to goldfishes'.
You can recognize them from their slim bodies, iridescent stripe, and bright red fins running from their nose to tail. Their bodies also have a unique silver color that shines yellow or blue, depending on the aquarium's lighting. You should get them in groups of at least ten so that the goldfish can't keep up if it tries to eat them.
Even with their speed, they are still in danger of getting eaten, especially when your goldfishes mature and grow way bigger than them.
3. Longfin Rosy Barbs
For longfin rosy barbs to work in your goldfish tank, you need to take the right steps. Firstly, they need to be kept in at least five groups as they tend to be overly aggressive if they're in small groups.
Get as many as you want because the bigger their group, the higher the chance they'll focus on each other and forget about your goldfish. Also, they're faster than your goldfish, and you have to ensure it gets enough food before the rosy barbs gobble it all up.
Also, you shouldn't have a problem dealing with them as they will eat most frozen foods, small pellets, and even flakes. They grow to about 6 inches - meaning your goldfish will not be able to eat them.
That also means your tank needs to be able to hold them all, so it should have a size of at least 30 gallons.
Want a bigger fish?
A bigger alternative to these is the Checker Barb. Unlike the other Barbs species, they aren't aggressive as long as you keep them in bigger groups. (ref. 2)
4. Zebra Danios
These are perfect companions for your fancy goldfish, and they are easily found online or in shops. They grow to about 2 inches, which means an adult goldfish can eat them. They will avoid getting eaten because they are much faster than goldfish.
Zebra Danios can survive in the same temperature range as goldfish and are usually better in groups of at least 6.
They are silver and black-striped, hence the name, and usually move together. They also like mild currents and would most likely be in filter outflows and bubble walls. These are areas goldfish tend to avoid.
Here’s the deal:
You might need to get artificial plants in your tank as a place for them to hide when they need to.
5. Bristlenose Plecos
Bristlenose Plecos will have no problem cohabitating with goldfish. They grow to about 5 inches and develop long tentacles around their snouts when they mature. Since they are algae eaters, they also help in cleaning up the tank.
Bristlenose plecos are peaceful fishes. If your goldfish tries to nibble on them, they have a spiny dorsal fin and armored body for protection. You'll find them hanging out on the tank sides and logs of your aquarium. Ten gallons of extra capacity might be necessary for your tank to keep them.
You might be wondering:
Some people online say plecos suck on goldfishes’ slime coat. From our experience, we have discovered that it only occurs when the larger plecos are not getting enough food.
6. Japanese Rice Fish
This fish is also referred to as the Medaka. It will thrive in brackish, marine, and fresh tanks at temperatures ranging from 64 to 72oF. Japanese rice fish grow to lengths of 1.6 inches, so you should consider getting tall plants in your aquarium so they can hide from goldfishes trying to eat them.
Keep them in groups of at least 10, so your goldfish won’t be able to nip at them. You'll need an extra 15 gallons in your tank capacity to hold a group of 10, so scale that up depending on how many you intend to get.
You might have a hard time getting this fish locally. However, you should find somewhere to purchase them online.
7. Banded Corydoras
Banded Corydoras are another species of bottom feeders that can help scavenge the left-over food from the goldfishes and clear the tank. They are generally peaceful but should be kept in groups of at least five because they are social fishes.
These fishes grow to lengths of 4 inches - making them too big for goldfish to swallow, so you're safe on that front. Their high sloped forehead, the cluster of barbels in their mouths, and flat belly make it easy for them to stay at the bottom and search for food.
They should be kept at temperatures of 61o-74oF, and you need a minimum tank size of 30 gallons.
But here’s the kicker:
It might be difficult finding them, especially in stores. If you can, they’ll make a wonderful addition.
How to Know If Your Goldfish Needs a Tankmate
Putting tankmates with your goldfish isn't necessary, but it's never a bad idea. Tankmates won't be detrimental to your goldfish's health as long as you consider the information below so they have enough space to swim and food to eat.
Type of Goldfishes
Before going out to buy tankmates for your goldfish, you need to identify the kind of goldfish. There are two main types of goldfish based on their tail design and shape: Fancy goldfish and hearty single-tail goldfish.
Fancy goldfish are smaller than their counterparts even as adults and cannot swim as efficiently as single-tailed goldfish. You can identify them from their bubble eyes, double tails, and round/hunched bodies that tend to slow them down in the water. If you have fancy goldfish in your tank, it would be better to get tropical tankmates. Check for the category of fancy goldfish you have and all the requirements it might need before selecting tankmates.
Hearty Single-tail Goldfish
These species have more limited choices for companions in the aquarium. Hearty goldfishes have a slim, streamlined body as well as a single tail. If you keep tropical fishes as tankmates for hearty goldfishes, they will eventually outgrow the tropical fishes, and this could become a disaster. The best companions for hearty tailed goldfishes are other single-tailed goldfishes and species that are comfortable in a pond.
Filtration and Aquarium Capacity
After determining the type of goldfish you have, next is to check your aquarium to see if you have adequate space to house extra fishes. You also need to confirm if your filtration system can handle the increased work of catering to more fishes. The smallest aquarium tank ideal for mature goldfish is a 20-gallon tank. For every extra goldfish, you need an additional capacity of about 10-20 gallons.
You need to consider the following:
- Goldfishes eat a lot and produce many biowastes. So they will need a good multi-stage filtration system to handle them and any tankmates you plan to introduce.
- Single-tailed goldfish use the entire tank for swimming, but fancy goldfish limit themselves based on their physical traits. You should look for a tankmate that likes an area your goldfish generally avoids.
- You might need to get logs, rocks, and other decors so other fishes can use them to hide from your goldfish if they try to eat them.
Selecting fishes that are compatible with your goldfish leaves you with many options and possibilities to explore. Depending on your tank’s size, your tankmates should ultimately depend on the breed of your goldfish and your aquarium setup. The safest option to go for would be other goldfishes as you won't have much to worry about.
If you choose other species as tankmates, you are also safe, and it can work out perfectly fine. Just make sure you take necessary precautions at each step and research the species you intend to introduce to the tank. Remember to consider all the tank conditions such as pH, temperature, diet, and aggression of the species before putting it in the tank.