What Fish Can Go In With Goldfish – Your Complete Guide To Peaceful
We’ve all been there. You look at your beautiful, charming goldfish gliding through their tank and think, “Wouldn’t it be nice if they had a friend?” It’s a natural thought! But as you start to research, the world of aquarium compatibility can feel like a minefield, filled with conflicting advice and horror stories.
Don’t worry, you’ve come to the right place. Finding the answer to what fish can go in with goldfish is one of the most common challenges aquarists face. I’m here to be your friendly guide, drawing on years of fishkeeping experience to help you sidestep the common pitfalls and choose the perfect tank mates for your water puppies.
In this complete guide, we’ll promise to show you everything you need for success. We’ll start by understanding the unique needs of goldfish, explore the absolute best (and worst!) companions for them, and give you a step-by-step plan for a peaceful introduction. Let’s build a thriving, harmonious aquarium community together!
Before You Add a Friend: Understanding Goldfish Needs First
Before we even think about adding new fish, we have to get one thing straight: goldfish are special. They aren’t your typical tropical fish, and treating them as such is the number one mistake aquarists make. Understanding their core needs is the foundation of a happy mixed tank.
Temperature is Non-Negotiable
Goldfish are temperate or coldwater fish. They thrive in cooler water, ideally between 65-72°F (18-22°C). Most of the popular fish you see at the pet store—like tetras, guppies, and bettas—are tropical and require water temperatures of 75-80°F (24-27°C).
Keeping them together means one species will always be stressed by the wrong temperature, leading to a weak immune system and disease. This is the most important rule in our what fish can go in with goldfish care guide: match the temperature requirements.
The Bioload Factor: Goldfish are Messy!
Let’s be honest: goldfish are the adorable, swimming pigs of the aquarium world. They eat a lot and produce a tremendous amount of waste. This waste, called bioload, quickly pollutes the water with ammonia and nitrates.
This means you need a very large tank with powerful filtration. A small tank will quickly become toxic. When adding tank mates, you are also adding to this bioload, so you must have the space and filtration to handle it.
Size and Temperament: Fancy vs. Single-Tailed
There are two main types of goldfish: slow, round-bodied “fancy” goldfish (like Orandas, Ryukins, and Fantails) and fast, torpedo-shaped single-tailed goldfish (like Comets and Shubunkins).
You should never mix these two types. The faster single-tails will outcompete the fancies for food and bully them relentlessly. For the purpose of this guide, we are focusing exclusively on tank mates for FANCY GOLDFISH in a large aquarium, as single-tails get far too large and boisterous for almost any tank mate other than Koi in a pond.
The Best Tank Mates: What Fish Can Go In With Goldfish?
Alright, now for the fun part! Finding the right friends for your fancy goldfish boils down to a few key criteria. A suitable tank mate must:
- Thrive in the same cool water temperatures.
- Have a peaceful, non-aggressive temperament.
- Be large enough not to be eaten by the goldfish.
- Not be a notorious “fin nipper.”
Here are some of the best, time-tested companions that fit the bill. This is your ultimate what fish can go in with goldfish guide to success.
White Cloud Mountain Minnows
These little gems are arguably one of the best choices. They are hardy, peaceful, and actually prefer the same cool water as goldfish. They are active swimmers that tend to stay in the upper levels of the tank, keeping out of the goldfish’s way.
Pro Tip: Keep them in a school of at least 6 to help them feel secure and see their best behavior. Their small size means they have a very low impact on your tank’s bioload.
Zebra Danios
Another fantastic option! Zebra Danios are incredibly hardy and active fish that also do well in a wide range of temperatures, including goldfish range. They are fast swimmers who will zip around the top of the tank, adding a lot of life and movement.
Like White Clouds, they are schooling fish and should be kept in groups of 6 or more. Their speed makes them difficult for a clumsy goldfish to bother.
Rosy Barbs
If you want a fish with a bit more size and color, Rosy Barbs can be a great fit. They are one of the most peaceful barb species and are tolerant of cooler temperatures. Their larger size means they won’t be seen as a snack by a fully grown goldfish.
Heads Up: Be sure to get the standard Rosy Barb, not a smaller variety. Keep them in a school of 5+ to ensure any playful chasing stays within their own group.
Other Fancy Goldfish
Sometimes the best friend for a goldfish is another goldfish! This is often the safest and most harmonious choice. Just remember to stick with other slow-moving fancy varieties and ensure you have enough tank space—at least 20-30 gallons for the first fish and 10-15 gallons for each additional one.
Bottom Dwellers & Cleanup Crew: Keeping the Tank Tidy
Many aquarists want a “cleanup crew” to help manage algae and leftover food. This is a great idea, but you have to choose wisely. Here are some safe and beneficial bottom dwellers.
Dojo (Weather) Loaches
These are a personal favorite and a perfect match. Dojo Loaches are peaceful, goofy, and thrive in cool water. They are excellent scavengers that will sift through the substrate for leftover food. Their eel-like shape and curious personality make them a joy to watch.
Nerite Snails and Mystery Snails
Snails are a fantastic, eco-friendly addition. Nerite Snails are algae-eating machines and cannot reproduce in freshwater, so you won’t have an infestation. Mystery Snails are larger and great at cleaning up, plus they come in beautiful colors.
They are completely peaceful and their hard shells protect them from curious goldfish mouths. This is a great way to introduce the benefits of what fish can go in with goldfish—a cleaner tank with more biodiversity!
A Strong Warning About Plecos
You will often see Common Plecos recommended for goldfish. This is dangerous advice. Common Plecos grow into two-foot-long waste machines that require massive tanks. More importantly, they have been known to develop a taste for a goldfish’s slime coat, latching onto the slow-moving fish at night and causing fatal injuries.
While some aquarists have success with Bristlenose Plecos, it’s still risky as their ideal temperature is higher than a goldfish’s. It’s often best to stick with the safer options above.
The “Absolutely Not” List: Fish to AVOID Keeping with Goldfish
Knowing what fish not to add is just as important as knowing which ones to add. Avoiding these fish will save you a lot of heartache. This is a critical part of understanding the common problems with what fish can go in with goldfish.
- Most Tropical Fish: This includes Bettas, Guppies, Mollies, Angelfish, and most Tetras. The temperature difference is the main problem.
- Aggressive & Fin-Nipping Fish: Tiger Barbs, most Cichlids (like Oscars or Jack Dempseys), and some Gouramis will bully and tear the delicate fins of fancy goldfish.
- Small Fish & Shrimp: Anything that can fit in a goldfish’s mouth, like Neon Tetras or Cherry Shrimp, will eventually become a very expensive snack.
- Common/Comet Goldfish: As mentioned, these fast swimmers will stress out and bully their slower fancy cousins.
Your Step-by-Step Guide: How to Introduce New Fish
Success isn’t just about picking the right fish; it’s about introducing them correctly. Following these steps is one of the most important what fish can go in with goldfish tips you’ll ever receive.
- Set Up a Quarantine Tank: This is non-negotiable for responsible fishkeeping. A simple 10-gallon tank with a filter and heater is all you need. All new fish should be quarantined here for 4-6 weeks to monitor for any signs of illness before they can infect your main tank.
- Source Sustainably: Whenever possible, support local fish stores that practice good animal husbandry or look for breeders who focus on health. This is a key part of sustainable what fish can go in with goldfish practices.
- Acclimate Slowly: When it’s time to move the new fish, don’t just dump them in. Float the bag in the main tank for 20 minutes to equalize the temperature. Then, slowly add small amounts of your tank water to the bag over the next 30-40 minutes to acclimate them to your water parameters.
- Release and Observe: Gently net the fish out of the bag (don’t pour the bag water in!) and release them into the tank. It helps to do this with the main tank lights off to reduce stress. Watch their interactions closely for the first few hours.
Frequently Asked Questions About Goldfish Tank Mates
Can I keep shrimp with my goldfish?
It’s very risky. While large Amano shrimp might survive with small goldfish, most shrimp (like Cherry or Ghost shrimp) are the perfect bite-size snack. It’s generally not recommended.
What size tank do I need for goldfish and friends?
Bigger is always better! We recommend starting with a 40-gallon breeder tank for two fancy goldfish. For every additional tank mate (like a school of danios or a loach), you should add at least another 10 gallons of water volume.
Are Dojo Loaches good tank mates for goldfish?
Yes, they are one of the best! They share the same temperature needs, are incredibly peaceful, and are excellent scavengers that won’t bother your goldfish. Their playful personalities are a huge bonus.
Why can’t I put a Betta fish with my goldfish?
There are two main reasons. First, they have opposite temperature needs: Bettas are tropical and need warm water, while goldfish are temperate and need cool water. Second, their temperaments can clash, potentially leading to fin nipping or aggression from either fish.
Your Path to a Peaceful Aquarium
Choosing friends for your goldfish doesn’t have to be a guessing game. By focusing on the core principles—cool water compatibility, a peaceful temperament, and appropriate size—you can confidently build a diverse and engaging aquarium.
Remember to prioritize the needs of your goldfish first with a large, well-filtered tank, and always, always quarantine new arrivals. This is the secret to long-term success and one of the most vital what fish can go in with goldfish best practices.
Now you have the expert knowledge to move forward. Go create that beautiful, active, and harmonious community tank you’ve been dreaming of. Happy fishkeeping!
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