15 Best Comet Goldfish Tank Mates – FishLab

Comet goldfish, sometimes called detailed goldfish, are one of the most popular freshwater fish for home aquarium enthusiasts to keep as pets.

Part of the carp family, these fish started to be bred specifically in the late 1800s as “pond fish”. It didn’t take long, however, for these fish to quickly flourish in a variety of different settings and today they are considered one of the perfect fish to keep for beginners.

Beautiful fish, with a distinctive tail that’s shaped like a comet (that’s where they get their name), these fish come in a range of different fiery colors. It’s not uncommon for them to have a blend of red, orange, yellow, and white, though sometimes their bodies have a more metallic sheen or a matte finish.

Growing up to 12 inches in length (when they are raised in the right kind of tank conditions) these fish have tails that can grow to make up 50% of their overall length.

Easy to find, relatively affordable, and hardy enough to be kept in a variety of different aquarium settings you don’t really have to babysit these goldfish the way you might other options.

That said, these fish do love to have other friends in the tank. That’s why we’ve put together this detailed list of the best comet goldfish tank mates you want to consider going forward.

Let’s jump right in!

What You Need to Know

These goldfish are super popular amongst home aquarium enthusiasts for a couple of different reasons – but mostly their beautiful and brilliant colors, their active and fun personality, and their relatively easy care level.

Below we dig a little bit deeper into the ins and outs of (almost) everything you need to know about keeping these fish in your aquarium.

Temperament

Comet goldfish live very active lifestyles, and have been pretty consistently described as fun, playful, and more than a little bit curious.

Make no mistake, these fish are very social. They live their best lives when kept in small groups and are not regularly aggressive or confrontational with other types of fish. You just want to be sure that you have plenty of room for all of your fish to sort of “stretch their legs” (so to speak)..

Average Size

As far as goldfish go, comet goldfish can grow to be quite long in length. It’s not at all uncommon for adult common goldfish to grow to be 10 to 12 inches in length (and sometimes even longer than that).

Don’t be surprised if your comet goldfish reaches their full length within the first year of their life, either. These fish grow very quickly when they have plenty of food and a large enough tank to stretch out in.

Competition

You won’t have to worry about your comet goldfish being very competitive.

These fish are not going to cause a lot of trouble with other fish species in your tank. They also don’t need a ton of space to swim around in – though they do produce a fair amount of waste. That’s why it’s a good idea to go for a larger tank, just to cut down on the amount of stress that extra waste might put on the immune system of all the fish living in your aquarium.

Water Parameters ; Tank Setup

A cold water fish through and through, goldfish do well in aquariums that have water temperatures that hover somewhere between 65°F and 75°F (or 18°C and 24°C). On top of that, these fish really prefer a water pH to be somewhere between 7.0 and 8.4. Do everything you can to make sure that the tank is very well aerated and swap out water regularly to avoid any water quality issues.  

As far as ideal tank sizes are concerned, you want to make sure that an individual comet goldfish has at least 30 gallons of water to work with all for themselves – and then an extra 10 gallons of water for every additional fish you’re going to add into the mix.

This will help all of your fish feel comfortable, secure, and give them plenty of room to swim around in.

On top of all of that, make sure that you have a softer substrate material and avoid adding sharp underwater plants or decorations into the mix. The scales on comet goldfish can be kind of delicate and you don’t want them to become injured.

At the end of the day, these fish are really pretty easy to keep happy and healthy!

15 Best Comet Goldfish Tank Mates

Also, you shouldn’t miss these other similar post:

• Blood Parrot Cichlid Tank Mates
• Giant Danios Tank Mates
• Lionfish Tank Mates
• Severum Tank Mates

1. Common goldfish 

• Scientific name: Carassius auratus
• Average adult size is 10-12 inches (25-30 cm)
• Care Level: Easy
• Origin: China

It should come as no surprise to anyone that you can keep other species of goldfish – especially common goldfish – in with your comet goldfish. These fish have similar care requirements, aren’t aggressive, and are super easy to take care of and keep healthy.

Pros of keeping with comet goldfish

• Thrive in the same water conditions

Cons of keeping with comet goldfish

• Produce lots of waste.  

2. Shubunkin goldfish

 

• Scientific name: Carassius auratus
• Average adult size is 8-10 inches (20-25 cm).
• Care Level: Easy
• Origin: Japan

This is another fantastic goldfish family member that you can add in with your comet goldfish. They have the same kind of peaceful temperament, have the same kind of playful curiosity, and enjoy the company of other goldfish just the same as your comets will.

Pros of keeping with comet goldfish

•  Hardy and resilient

Cons of keeping with comet goldfish

• Can grow to dwarf other fish in the tank

3. White Cloud Mountain minnows 

• Scientific name: Tanichthys albonubes
• Average adult size is 1.5 inches (4 cm)
• Care Level: Easy
• Origin: China

Small, super peaceful fish that get along with pretty much anyone and everyone in the aquarium you can’t go wrong adding these into the mix with your goldfish. It doesn’t hurt that they have similar tank parameter requirements and are just as easy to care for, either.

Pros of keeping with comet goldfish

• Peaceful and friendly, easy to care for

Cons of keeping with comet goldfish

• May become snacks for larger comet goldfish

4. Zebra danios 

• Scientific name: Danio rerio
• Average adult size is 1.5-2 inches (4-5 cm)
• Care Level: Easy
• Origin: India, Bangladesh, Nepal, and Bhutan

Very active fish, these beautiful little underwater creatures are going to speed around your comet goldfish tank more than your goldfish might. But that’s not going to frustrate any other tank mates! These energetic, beautiful, and funny fish are really peaceful and good companions for goldfish.

Pros of keeping with comet goldfish

•  Hardy and strong, very active

Cons of keeping with comet goldfish

•  Fin nippers, thrive in slightly cooler water temps

5. Cherry barbs 

• Scientific name: Puntius titteya
• Average adult size is 2 inches (5 cm)
• Care Level: Moderate
• Origin: Sri Lanka

You’ll never have to worry about these fish getting cross with your goldfish. They are very peaceful, generally pretty easy to care for, and enjoy the same kind of tank conditions. Just make sure that they have plenty of room to swim around in.

Pros of keeping with comet goldfish

•  Peaceful and relaxed, hardy

Cons of keeping with comet goldfish

•  Can get eaten by bigger comets

6. Bristlenose plecos 

• Scientific name: Ancistrus sp.
• Average adult size is 4-5 inches (10-13 cm)
• Care Level: Easy
• Origin: South America

A fantastic tank mate for your goldfish, these bottom dwelling fish are going to work double overtime to keep your tank clean and your water healthy. They can grow to a decent size, though, so make sure that there’s plenty of water for everyone to feel comfortable.

Pros of keeping with comet goldfish

•  Algae eaters, keep tanks clean

Cons of keeping with comet goldfish

•  Pump out a lot of waste, requiring frequent water changes

7. Corydoras catfish 

• Scientific name: Corydoras sp.
• Average adult size is 2-3 inches (5-8 cm)
• Care Level: Easy
• Origin: South America

Another top-tier tank companion option for comet goldfish, these fish are going to work to keep your tank clean, are peaceful and friendly, and aren’t going to take up too terribly much space in your aquarium.

Pros of keeping with comet goldfish

•  Peaceful, live in the bottom water column

Cons of keeping with comet goldfish

•  Will bite and nip the fins of comet goldfish

8. Rosy barbs 

• Scientific name: Pethia conchonius
• Average adult size is 2.5 inches (6 cm)
• Care Level: Moderate
• Origin: India, Pakistan, and Nepal

While these fish are going to lead a very active lifestyle, they aren’t going to bother your goldfish any – and they probably won’t pay your goldfish any mind on their own, either. They are beautiful to look at and fun to watch race around, though.

Pros of keeping with comet goldfish

• Capable of living in a wider range of water conditions

Cons of keeping with comet goldfish

• Will sometimes pick fights with smaller comets

9. Kuhli loaches 

• Scientific name: Pangio kuhlii
• Average adult size is 3-4 inches (8-10 cm)
• Care Level: Moderate
• Origin: Southeast Asia

Since these fish are bottom dwellers they are going to stay in the lower level of the water column. This keeps them out of the way of the larger comet goldfish that you have. But even if they mix and mingle you don’t have anything to worry about. These are super friendly fish.

Pros of keeping with comet goldfish

•  Bottom dwellers, these fish won’t interact much with your goldfish

Cons of keeping with comet goldfish

•  Can outgrow smaller tanks pretty quickly

10. Neon tetras 

• Scientific name: Paracheirodon innesi
• Average adult size is 1.5 inches (4 cm)
• Care Level: Easy
• Origin: South America

Small, easy to care for, and a great companion for any goldfish species, you don’t have much to worry about when it comes time to add neon tetras to your tank. You’ll love the added punch of color and personality these fish bring to the table, though.

Pros of keeping with comet goldfish

•  Small, perfect for smaller aquariums with comets

Cons of keeping with comet goldfish

•  Prefer slightly warmer water than comets will tolerate

11. Harlequin rasboras 

• Scientific name: Trigonostigma heteromorpha
• Average adult size is 2 inches (5 cm)
• Care Level: Easy
• Origin: Southeast Asia

The only thing you’ll want to consider when adding these fish to your goldfish aquarium is that there is enough water for everyone to “keep the peace”. These fish are active, like to stretch out, and can take up even more space than the considerably larger comet goldfish (believe it or not).

Pros of keeping with comet goldfish

•  Small enough to be kept in comet goldfish tanks without crowding things

Cons of keeping with comet goldfish

•  Like to zip around the tank, sometimes stressing out comets

12. Swordtails 

• Scientific name: Xiphophorus helleri
• Average adult size is 4-6 inches (10-15 cm)
• Care Level: Easy
• Origin: Central America

Aggression won’t ever be a worry when you have these fish in the tank with your comet goldfish. Peaceful, easy-going, and relaxed, these fish are still a lot of fun to watch.

Pros of keeping with comet goldfish

• Hardy and thrive in all kinds of water conditions

Cons of keeping with comet goldfish

•  Can produce a lot of waste, requiring the tank to be filtered and clean more often

13. Platies 

• Scientific name: Xiphophorus maculatus
• Average adult size is 2.5 inches (6 cm)
• Care Level: Easy
• Origin: Central America

The cool thing about these fish is that they require almost identical water conditions to the ideal tank setup for comet goldfish. It doesn’t get much easier than that!

Pros of keeping with comet goldfish

• Strong swimmers, like the same water parameters comets enjoy

Cons of keeping with comet goldfish

• Somewhat sensitive to disease

14. Mollies 

• Scientific name: Poecilia sphenops
• Average adult size is 3-4 inches (8-10 cm)
• Care Level: Moderate
• Origin: Central America

A very peaceful fish, these beautiful little underwater swimmers will add a pop of color to your aquarium and a lot of personality as well. They get along really well with comet goldfish.

Pros of keeping with comet goldfish

• Peaceful and relaxed, fast swimmers

Cons of keeping with comet goldfish

• Can be a snack for bigger, more aggressive comets

15. Guppies 

• Scientific name: Poecilia reticulata
• Average adult size is 1.5-2 inches (4-5 cm)
• Care Level: Easy
• Origin: South America

It’s difficult to imagine a friendlier species of fish (aside from goldfish, anyway) than guppies. You can’t go wrong with these swimming in the same aquarium as your comets.

Pros of keeping with comet goldfish

• Easy to get along with

Cons of keeping with comet goldfish

•  Small but can breed rapidly, overwhelming a tank population

Summary

So there you have it, pretty much everything you need to know about the 15 best tank mates for comet goldfish!

Like we mentioned a little while ago, goldfish are very social and very friendly fish. It’s never a bad idea to give them a couple of extra fish to play around with – especially if you pick suitable companions from the list we highlighted above.

Best of luck going forward.

Frequently Asked Questions

What should I feed my comet goldfish?

Your goldfish are going to be omnivores, which means you want to give them a balanced diet of quality fish food. Commercial pellets, fish food flakes, and maybe even some fresh or frozen vegetables every now and again will keep them happy and healthy.

How often should I change the water in my comet goldfish tank?

As a general rule of thumb it’s a good idea to swap out between 10% and 20% of the water in your aquarium once a week when you have goldfish in the tank.

Can comet goldfish live in a bowl or small tank?

The last place you want to keep a comet goldfish is in your typical “goldfish bowl”. These fish need at least 30 gallons of water to thrive all on their own, and an extra 10 gallons of water for each fish “roommate” they have in the tank. Small goldfish bowls or tiny tanks will stunt their growth and threaten their health and wellness.

Do comet goldfish need a filter and air pump in their tank?

If you want to be sure that your comet goldfish are as healthy as possible it’s a good idea to have a water filter and an air pump in your aquarium. This will keep oxygen levels up, will filter out and remove waste from the water, and will even add a little bit of circulation and current to the tank, too.

Can comet goldfish live with other fish in the same tank?

Your comet goldfish will have a lot of fun with other comet goldfish in the tank, as well as a whole host of other species of fish (like the 15 we highlighted earlier). Keep overly aggressive fish out of the tank, though, and you won’t have anything to worry about.