While everyone wants a colorful and interesting variety of fish in their tank, not every type of fish will be
able to live together.
Two incredibly popular types of fish are goldfish and corydoras. Both of these fish have very passive and
peaceful personalities but does that mean they can safely live together?
If you are looking to keep goldfish and corydoras as tank mates then read on to see if this is something that
I’d recommend or if it could potentially be a major issue…
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Can Goldfish Live With Corydoras?
Goldfish can only live with corydoras in very rare and specific circumstances. For the most part,
however, goldfish cannot live with corydoras as they require different water temperatures and the
size of tank needed to keep both species is significantly larger than what most fish keepers will have
.
When considering which different species can live together in a tank, the most important factor to first
consider is what environment these fish are most adapted to
.
In most pet stores, you will see the fish separated by cold water, tropical, and temperature species while
each category will require different requirements for care and maintenance.
Goldfish are coldwater fish while corydoras are tropical fish. This first indicator is enough to demonstrate
that naturally, goldfish and corydoras might not be the most well-suited tank mates to live together.
Despite this, there are actually a number of owners who have tried to keep goldfish and corydoras together
with varying levels of success.
If you watch the video below, you can clearly see that an owner has managed to keep his cory catfish with
goldfish and has had no issues. He even states that he didn’t believe that they would be compatible as a
result of the different water requirements but they seem to be thriving just fine.
The scenarios like in the video above are unfortunately quite rare. The majority of the time, you will come
across noticeable issues when trying to keep goldfish and corydoras together so read on to see what some of these issues are.
Issues With Keeping Goldfish and Corydoras Together
While there is certainly an element of risk with keeping a goldfish and corydoras together, mainly due to
their individual requirements and tank parameters, It can be possible in some circumstances for these two
types of fish to coexist.
Personally, I would avoid keeping goldfish and corydoras together as tank mates if possible as they are not
well suited to living together. Some people can successfully keep them as tank mates however the
requirements are really quite specific if you wanted to do so.
Below, I’ll provide an example of all the factors to consider when looking to keep goldfish and corydoras
together and demonstrate just how difficult it can be.
Size of Your Fish
The number one issue to keep in mind when keeping any different breeds together in a tank is the size of
ALL of the fish in the tank. A combination of fish with large mouths and smaller fish means that it’s very
common for fish to be eaten by their tank mates.
When it comes to goldfish and corydoras, this is the biggest concern that most fish keepers have. Some
breeds of goldfish can have quite big mouths that can easily fit smaller corydoras and this is something that
can surprisingly lead to the death of both fish!
The reason for this is that corydoras have spikes and spines throughout their body and fins which,
according to Wikipedia, act as a defensive and survival mechanism. It’s common for goldfish to accidentally
eat a corydoras only for the spikes to be activated and get stuck in the goldfish’s mouth or throat.
These spikes also contain venom that is not harmful to humans but they are to other fish. If your corydoras
is of a small breed and accidentally gets eaten by a goldfish, the likely scenario is that both fish will end up
dying.
Tank Size
Directly related to the size of your fish is the size of your tank. Goldfish can grow to significant sizes and so
can cories depending on the breed (cory catfish, in particular, can grow to be quite large). Large fish
ultimately require larger tanks to have space to swim around and also to preserve the water quality.
While goldfish can be quite resilient fish and live comfortably in “poorer” quality water, corydoras on the
other hand are very susceptible to any dirty water and can get sick quite easily when living in poor quality
water.
A large tank will therefore be essential to keeping the water clean and optimal at all times but even then,
you will still need to produce more regular water changes than you would with a tank of just goldfish alone.
Goldfish have significant water requirements in terms of tank volumes and Fish KeepingWorld
recommends that most goldfish will need a minimum of 20 gallons of water per goldfish (while some breeds
can require up to 50 gallons each).
Water Temperature
Another important factor to consider is the water temperature in your tank. Goldfish are coldwater fish and
corydoras are tropical fish meaning they require warmer temperatures.
A goldfish will need temperatures of 65ºF to 75ºF and while some breeds of corydoras could survive in the
colder temperatures, it’s not something that I would advise for a number of reasons:
● Firstly, most breeds of corydoras require warm temperatures of 75ºF to 80ºF to live comfortably.
While some can live in colder temperatures, they will only be surviving instead of thriving.
● Corydoras can survive in colder temperatures, however, this carries significant risk as it can expose
your cory to potential illness, difficulty adapting, and in some cases, even death.
According to BuildYourOwnAquarium, Panda corydoras are one of the few cory breeds that can live in
waters with temperatures varying from 60ºF to 75ºF. Therefore, if you are looking for breeds of corydoras
that can live with goldfish, the panda cory is one of the few exceptions (though even these would not be
recommended!).
Feeding
Feeding can also be an issue when keeping goldfish and corydoras together. While the goldfish won’t have
any issues, corydoras are bottom-feeding fish and you might find it difficult to properly feed them alongside
goldfish.
Goldfish will tend to eat all of the food before it even makes it to the bottom of the tank. Specialist feeding
methods (like feeding your corydoras in spaces that the goldfish can’t get into) are therefore required which
can be time-consuming and frustrating.
Groups
Goldfish are not the most sociable of fish and you can quite comfortably keep 1-2 goldfish without them
displaying signs of anxiety or loneliness. Corydoras however are schooling fish, and in order to keep them
happy, it is advised that you keep them in a group of around 6.
This, therefore, ties back into my point earlier about tank size, while corydoras are usually a small breed
and do not require much room, a group of 6 will need around 10 – 30 gallons to live comfortably (depending
on the breed).
Therefore, if you have 1 goldfish and a school of 6 corydoras, you’d need a tank size of around 50 gallons as a minimum.
How to Keep Goldfish and Corydoras Together in a Tank
After looking at the above, it’s clear to see that goldfish and corydoras are not the most ideal tank mates
and if possible, they should not be kept together. With that said, there are a few instances whereby a
goldfish and corydoras can live together.
- Ensure both types of fish are well suited to the water temperature. A good temperature for certain
types of goldfish and corydoras could be 75ºF but the breed of each will determine this.
- Make sure the corydoras are too big to fit in the goldfish’s mouth. If a goldfish accidentally gets a
corydoras stuck in its mouth, it could eventually lead to the death of both the fish.
- Make sure the tank has enough water capacity for your number of goldfish and a small school of
corydoras. Between 30 – 50 gallons should be a minimum for this combination of fish
These requirements are so specific that it’s not a realistic expectation for your goldfish and corydoras to live
together. Whilst there are circumstances where it could work, there are simply more suitable tank mates
and different types of fish that you should consider instead.
Conclusion
Goldfish and corydoras are both very popular breeds and relatively easy to look after and for this reason,
many people will wonder whether they can live together or not.
While in some instances these two types of fish can live together, I would strongly advise against this.
These fish are not well suited to living together and if you try to force it, you could end up with your fish
becoming ill and potentially dying.
