How Many Koi Fish Should Be In A 75 Gallon Tank? ( Suitable tank sizes for koi)

Koi Fish Should Be In A 75 Gallon Tank

As a fish keeper and an aquarium lover, your priority is to keep your pets comfortable and happy in their tanks. Let’s say you love koi and you want to have them as pets, but you are only budgeting to buy a 75-gallon tank. Now your question might be, will it contain a koi? and how many of them could live comfortably in such a tank. If the above defines you, that means you want to find out how many Koi you could have in a 75-gallon tank, then this article is definitely for you.

How many Koi should be in a 75-gallon tank? Koi are big fish that could grow up to 2-3 feet in size. A 75-gallon tank is too small to contain such fish, unless when they are still small.

Koi Fish Should Be In A 75 Gallon Tank

As a fish keeper, your main concern is to make sure your fish, etc are comfortable and are well taken care of.

No animal could survive or at least do well in a non-suitable or comfortable environment and fish is among those animals that are easily affected by a non-suitable environment.

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Koi are quite large when they mature.

They are cold and freshwater dwellers and are sometimes very aggressive to their tank mates and even to themselves.

They love swimming about in the water and eating whatever they find suitable for them to eat.

The truth is, keeping this kind of fish is very expensive unless you already have a very large tank to harbor them, as you will need to buy a huge tank to keep them.

The bitter truth here is, you can’t keep a Koi in a 75-gallon tank!.

So don’t try it, unless the koi is still very tender, then you could keep maybe 2 or 3 of them in such a small tank.

Although a 75-gallon tank is quiet large for so many aquatic animals to live comfortably and even in groups too.

But when it comes to keeping a huge fish like koi, trust me, one koi is almost or should I say impossible to be kept in just a 75-gallon tank, as it won’t feel comfortable and won’t move about, which will definitely hurt the fish if it stays there for a while.

Don’t get me wrong, you can still keep 2 or 3 of them in this type of tank, but you can only do so when the fish are still tender and have not attained full size, but once they reach 15 – 20 inches in size, then you must need to get them a bigger tank of up to 250 – 500 gallons, depending on how many you have in the tank.

Can Koi Live in a 75 Gallon Tank?

As I mentioned earlier in this article, koi are big fish when they grow up and do require a very big space for them to be very comfortable.

Can Koi Live in a 75-gallon tank? Yes, they could be kept in a 75-gallon tank, but only when they are still small.

If you have a 75-gallon tank and you still feel like having this type of fish, then you can still make use of your 75-gallon tank, as it is not useless.

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What you will do is to get baby Koi and raise them in your tank, having in mind that you will still need to get a far bigger tank as they grow.

So you can still keep your Koi fish in a 75-gallon tank.

How Big Of A Tank Do I Need For 2 Koi Fish?

If you plan to have at least 2 koi fish in your aquarium, you might want to know how big of a tank you could get for them.

How big of a tank do I need for 2 Koi Fish? For 2 large Koi fish to be comfortable, they need nothing less than a 250-gallon tank.

Like I always say, keeping your pets happy should be your priority as a fish keeper.

So for 2 adult Koi to be happy and comfortable in their tank, they need enough space to move about and play.

So if you have 2 koi fish that are still growing, then get them up to a 250-gallon tank.

How Many Gallon Tank Do 4 Koi Need?

Let’s say you have 4 of this type of fish or you are planning to get at least 4 of them from a pet shop and you are wondering how big their tank should be.

How many Gallons do 4 Koi need? 4 adult Koi fish needs up to a 700-1000 gallon tank to be comfortable.

Normally, each adult Koi fish could grow up to 2-3 feet in size, so a fish of such size needs a bigger space to be okay and have enough to swim around in its tank.

Related: How many Hermit Crabs could live in a 75-liter tank?

So if you ask me, I would suggest buying a 1,000 Gallon tank for 4 of these fish.

How Many Gallon Tank Does 1 Koi Fish Need?

If you are to keep a single koi in an aquarium, then you should keep it in a 200-250 gallon tank.


You can hardly keep a medium size Koi in a 75-gallon tank, even to talk of an adult Koi.

So the fact is, you can’t keep an adult Koi in a tank that’s less than 200 gallons and expect it to be totally okay.