Goldfish are one of the most popular aquarium fish for beginners. When people think of aquariums, they think of a single goldfish in a fish bowl. Of course, this raises the very common: Can two goldfish live together?
Yes, two goldfish can generally live together given they have enough space in the tank. Goldfish are a social aquarium fish and generally not too territorial or aggressive, so they can easily live together. However, there are some things you must know before you simply plop two goldfish in a tank together. And this article will cover all you need to know about having multiple goldfish in the same fish tank.
Requirements To Have More Than Two Goldfish in an Aquarium
While you can have two or more goldfish in the same tank, there are some things that you must know before doing this to ensure that the goldfish stay at their absolute healthiest. This section will cover some things to do before embarking on a multi-goldfish fish tank.
Same Breed of Goldfish
Did you know that there are over 100 different breeds of goldfish?
That’s right. In fact, there are hundreds of different breeds of goldfish out there, but the basics are pretty easy to understand.
There are long bodied goldfish (comet, common goldfish, etc.) and fancy goldfish. Fancy goldfish are identified by their egg shaped body and much fancier features like odd shaped heads (ranchu goldfish) or big eyes (Demekin). There are obviously more than just those two breeds of fancy goldfish.
You generally know a fancy goldfish breed when you see it.
Anyway, it’s important to only keep goldfish of the same breed in a tank together. Why is it so important to do this?
Different goldfish breeds have different swimming abilities. The main difference is that most fancy goldfish cannot swim very well, which causes problems when you mix fancy goldfish with long-bodied goldfish as the long-bodied goldfish tend to harass the fancy goldfish.
It also creates a feeding problem as the fancy goldfish are much slower to get the food you feed them.
To summarize, don’t mix different goldfish breeds together IF the swimming strength of the different breeds is too great. It’s just a disaster waiting to happen. Not to mention that fancy goldfish are much more sensitive to water conditions than the more common goldfish varieties (comet, common goldfish, etc.).
Similar Sized Goldfish Go Together
Next, goldfish that are a similar size go together. Those that are different sizes generally do not go together.
Goldfish don’t each other as a rule. However, bigger goldfish will eat baby goldfish if the big goldfish can fit the baby in its mouth. As mentioned many times on this site, goldfish eat pretty much anything that they can fit in their mouth. Baby goldfish are no exception to that rule.
Now, I’m not saying the goldfish need to be the exact same size to live together. Just don’t put a baby goldfish in with an adult goldfish, unless you want the baby to disappear, and you’ll be fine.
This one should be common sense, but it’s worth mentioning.
You need enough space to have multiple goldfish in the same tank.
The general rule is 10 gallons per flat bodied goldfish and 20 gallons per fancy goldfish.
Personally, those tank sizes are small for a goldfish in my opinion. I’d recommend doubling it unless you have an amazing water filter, lots of plants, and/or like doing a lot of water changes.
Goldfish are some of the dirtiest aquarium fish you can own because they don’t have stomachs. Food simply passes right through them. And, to make things even more difficult, goldfish are also one of the more sensitive aquarium fish.
A double whammy for frequent water changes.
With that in mind, 20 gallons per goldfish and about 30 gallons per fancy goldfish is a good rule of thumb for optimum goldfish health and easier maintenance.
Good Filtration and Plenty of Water Changes
Finally, if you want to have more than one goldfish in the same tank, then you need gold filtration. You can’t have more than one goldfish in a tank with a cheapo Wal-Mart filter (unless you have a lot of plants).
Goldfish are simply too messy and too sensitive for that.
Additionally, you will have to change 100% of your water at least once a week. The percentage obviously decreases as your tank size increases. That’s one of the funnier things about fish tanks – bigger tanks are easier to maintain than smaller tanks.
My Recommendation for Multiple Goldfish
So, my personal recommendation for multiple goldfish in the same tank is to use a bigger tank. I would not both putting goldfish in a tank less than 55 gallons, personally.
It’s just too much work with water changes and filtration. 55 gallons gives you enough wiggle room to have multiple goldfish while not having to worry about coming home to all your goldfish floating upside down in your tank.
How Do Pet Stores Keep So Many Goldfish In The Same Tank?
I am anticipating this question, so I’ll get ahead of it and answer it right now. There are a few reasons that pet stores have so many goldfish in the same tank. Here is a brief explanation:
- Pet stores have an extensive filtration system that covers multiple tanks.
- Pet stores don’t mind if some goldfish die – the fish are generally low cost and extra tank maintenance is not worth saving a few extra 5 cent fish. Harsh, but that’s the truth.
- Pet stores only hold the goldfish temporarily.
That covers it for why pet stores have so many goldfish in a small tank. On that note, you generally won’t see pet stores having fish that cost over $1,000 in unideal conditions – a $1,000 fish dying hurts a lot more than a goldfish that costs a nickel.
That covers it for if two goldfish can live together.
Yes, two goldfish can live together – easily. Goldfish don’t eat each other unless there is a huge size discrepancy (ie. adult and baby) and they generally won’t get into territorial fights like tropical fish.
The main bottleneck on having two or more goldfish in the same tank is aquarium size and water maintenance. You need a big tank and you will have to do a good job keeping the water conditions ideal.