Skip to Content

How Many Goldfish in a 75 Gallon Tank? (Explained)

Goldfish is an ornamental fish. When you put two-three goldfish inside of the aquarium, you will highly be likely to look at the aquarium for more time than usual.

These fishes are domesticated about 2000 years ago. So how many goldfishes can fit in a 75-gallon tank? Let’s see.

How many goldfish in a 75 gallon tank?

Goldfish, though it is small, needs relatively bigger space. In a 75-gallon tank, you can easily keep 4 goldfish. For the first fish, you will need a 20-gallon tank. You must add an additional 10-gallon when you add an extra goldfish to the tank. The minimum tank size for a goldfish is 20-gallon.

Not all goldfish require the same amount of size. According to different breeds you need to have different size of the space. Let’s know about them.

Fancy goldfish:

Fancy goldfish is peace-loving fish. They come with a distinctive color on their head, and they have beautiful scales as well. They don’t need to take extensive care, easy to medium level of care is enough for them. They live for almost 10 years.

A single fancy goldfish needs at least 20 gallons of water. Four of these small goldfish can live in a 75-gallon tank.

Fantail goldfish:

As the name suggests, the tail of these red-orange egg-like goldfish is quite popular among those people who love to keep goldfishes. Though the small space of their body keeps a little room for their organs to fit in.

This fish can get up to 8 inches long, and live up to 10 years. The minimum tank size required for a single goldfish is 10 gallons to 20 gallons.

Comet goldfish:

A playful as well as peaceful aquarium inhabitant fish is the comet goldfish. These fishes are yellow or orange in color. They grow up to 12 inches and they live for almost 14 years. Which is more than any other species of goldfish.

But the tank size of these species requires a little more than usual. A single fish needs at least a 50-gallons tank.

Small goldfish:

There are no specific small goldfish species, but the celestial, bubble eyes, pearl scale, and oranda are some of the smallest species you will get to have in the market.

The Pearl scale is the smallest species among others, as they can grow from 1 inch to 4 inches. For them, you need to have a basic 20-gallons tank and any less than this size is not recommended.

Common goldfish:

Common goldfish is one of the many species that can grow up to 12 inches. This species of goldfish, love to stay alongside other species of fish.

These fish are not aggressive. And they need a minimal level of care, and these fishes come in various colors and patterns. A single common goldfish needs at least a 20-gallons tank.

Feeder goldfish:

Feeder goldfish also extend their life to almost 15 years. Along with that, they can reach up to 12 inches, and these fishes stay together but they can live alone as well. They are not peaceful or aggressive.

A single feeder goldfish needs a 20-gallon tank. These multicolored fish is quite available in the market.

Oranda goldfish:

Oranda goldfish is a small goldfish variant. Oranda goldfish is a fancy goldfish. These fish need more care than usual goldfish.

These fish come in different patterns and colors. The size of these fish can get up to 9 inches. They need more tank space. Single oranda goldfish need a 30-gallon tank.

How big can goldfish get in a 75 gallon tank?

There are about 200 goldfish species. Every goldfish’s species is different from one to another. The differences are visible in their behavioral pattern, their food habit, their space of living, and their aggressiveness.

Like the Ryukin goldfish can get up to 8 inches in a fish tank of 20 gallons. On the other hand, a single Shubunkin goldfish need 75 gallons of the tank to grow up to 18 inches.

 One thing to notice here is the species’ minimum space requirements, the water, and the food and care the fish is getting. If a species needs 10 to 20 gallons minimum, and it gets a 75-gallon tank, it will likely get bigger faster under the condition that it gets proper food.

So, a single goldfish can get 4 to 18 inches in a 75 gallons tank.

Can a 75 gallon tank be too big for a goldfish?

Goldfish require more space to live. If you put too many goldfishes in a tank, then there you will have more bacteria generation and more diseases in those goldfishes. If goldfish can get more space to swim, and eat food, they will grow faster.

Also, they will get stronger than the fish that are staying in a small space. So, 75 gallons is not too big for some species that don’t require to have more space than 10 to 20 gallons each.

But some species require to have a minimum of 75 gallons tank, at that time it becomes mandatory to provide a 75-gallon tank to those species. So, any size of tank more than the minimum requirement is good for a goldfish.

Four factors that determine how many goldfish can live in a 40 gallon tank

There are some facts that determine how much space should the goldfish have. Let’s get to know about them.


Size matters. In general, a single goldfish needs to have 20 gallons tank without any other mates. And any additional fish will need to have 10 more gallons.

So, following this pattern, we can say in a 40-gallon tank can take at least 2 to 3 small goldfish.


If the species that are put inside of the tank are aggressive, then they must need more space. The Ryukin goldfish species is known to be an aggressive goldfish species, they are commonly known as the bully goldfish.

Though this goldfish species requires a minimum of a 20-gallon tank. So, you need to consider what species of fish you are putting in the tank.


Different species require different sizes of the tank. Keeping this in mind, most of the goldfish species as stated before, need to have a 20-gallon tank.


The immunity of species differs as well. So, if you put more immune species in a congested place, they will highly be likely to live longer. This is one of the most important factors.

How to take care of goldfish in a 10 gallon tank?

Taking care of the goldfish ensures their long life. But for that you need to make sure that you take care of them well. Let’s get to know how you can take care of your goldfish.

Provide a miniature home inside of the tank:

A miniature home is not mandatory, but it will help the fish not to get bored or depressed. If the goldfish become bored, it will eventually be depressed and it will formulate diseases in the fish.

Clean the Tank Regularly:

Cleaning the tank is mandatory because generally minimum 20-gallon tank is required for a single goldfish. But as the tank is 10 gallons in size, you need to clean it so that bad bacteria cannot infest inside.

Change the water every 3 days:

This is a standard of changing the water. But, as you are taking care of a goldfish in a 10-gallon tank, you might need to change the water more than once in 3 days.

Don’t provide extra food:

Extra food will end up sedimented or floating around the water. Which will eventually make the water bad. That’s why give a limited amount of food to the goldfish.

Don’t overcrowd the tank:

The minimum size of the tank is 20 gallons. Here as the tank size is only 10 gallons, you must be careful about the tank is not overcrowded. Or it will hamper the growth of the fish.

What fish can I put in 75 gallon tank with goldfish?

As for 75 gallon tank is quiet big, you may want to accompany your goldfish with other fishes. But you cannot just put any fish in the tank. You need to know what fish you can put in. Let’s get to know what fish you can put in the tank with goldfish.

Rosy Barb:

Rosy barb seems the same as the goldfish. As generally, 75 gallons is quite large, you can keep some of these species along with goldfish. Rosy barb, on the hand, is a peaceful fish species.

Platy Fish:

Platy fishes come with different and unique scale patterns and color combinations. These fishes are about 2 inches tall, and they need only 10-gallon-sized tanks. So, they can live peacefully with goldfish.

Bristle nose Pleco or Sucker Fish:

These fishes are kept eating any extra food, plankton, or anything bad inside of the tank. Also, they stuck with the border, that they don’t bother other fishes in the tank. They can be a good mate for goldfish.

Hillstream Loach:

Hillstream loach is one of the unique shaped and patterned fishes. These fishes are thought to be miniature stingrays as well. These fish are also like the sucker fishes.

Final Thoughts

Goldfish is one of the finest ornamental fish, that needs the least amount of care. When you provide them space to swim around, they can easily live. In a 75-gallon tank, four of them can live without any problem. If you put a single fish in a 75-gallon tank, it will be good for the goldfish.