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How Many Goldfish in a 30 Gallon Tank? (Answered)

There are different varieties of goldfish. The number of goldfish swimming around the world is two hundred. As goldfish is one of the most popular fish to pet. And there is a huge variety of goldfish to choose from. How many of them can live in a tank of 30-gallon? Let’s find out.

How many goldfish in a 30 gallon tank?

Goldfish is one of the cutest and most beautiful pet fish people want to keep. Two goldfish can easily stay in 30 gallons tank. And goldfish need a companion to stay active and healthy. 20 gallons is suggested for one goldfish, and any additional goldfish need another 10 gallons.

As goldfish tend to grow bigger, you should be careful about putting too many in a single tank. Let’s get to know how many of the different types of goldfish can live in a 30 gallon tank.

Fancy goldfish:

Fancy goldfishes belong to a unique group of goldfishes. Their look varies from one to another, bringing a glamorous vibe to the aquarium.

They are beautiful and unique in look, but the most beautiful thing about them is they don’t need any special treatment. Two fancy goldfish can live easily in a 30-gallon tank.

Comet goldfish:

Comet goldfishes can vary from four inches to direct twelve inches. They can live for 14 years. Comet goldfishes are the most popular among 200 goldfish species. This fish has been kept as a pet for more than 200 years.

A small comet fish must need to have 20 gallons at least to stay fit. On the other hand, goldfish cannot stay below a 50-gallon tank for an adult comet.

Fantail goldfish:

Both the beginner and the experienced fish keepers handle fantail goldfish easily. That’s why this variant is easily cared for and loved by everyone. These fantail goldfish can be found so effortlessly, and they are easy to take care of.

Generally, this species of fish stays alive maximum for of 8 years. A single fantail can fit in a minimum tank size of 20 gallons. In addition to adding new fantail fish with an existing fantail, extend the tank at least 10 gallons.

Oranda goldfish:

From the 15th century, Oranda goldfishes are here as a pet. Wild carp is the ancestor of oranda goldfish. These fishes are so fancy and loved by people that they are still people’s favourite to this date.

The size of these goldfish, when they are adults, is quite large. Which is 8 to 9 inches long. These fish can stay about 15 years. These fish can fit inside of a 20 gallons tank. But they can live happily in a 30 gallons tank.

Common goldfish:

The longest time a goldfish has stayed is for 43 years. The fish was called Tish. The variant the fish Tish was belonged to was a common goldfish.

Common goldfishes are almost the same as comet goldfish. People confused common goldfishes with comet goldfishes. These fish can fit inside 20 gallons of the tank.

Can a goldfish live in a 30 gallon tank?

There are two hundred species of goldfish living on earth. On average, goldfishes need to have 20–30-gallon tanks so that they can live easily. But for a single comet goldfish, they need to have 50-gallon tanks, to stay fit and live without any problem.

A fancy goldfish can easily stay in 30 gallons of a tank for 3 to 5 years. If someone wants to add more goldfish to a 30 gallons tank, adding an additional 10 gallons per fish is recommended.

Goldfish has the tendency to wastewater more than any other pet fish. So, it is better to give more room to these tropical fishes.

How long can goldfish live in a 30 gallon tank?

A goldfish can live in a 30-gallon tank. Even most of the goldfish species doesn’t need to have to space more than 20 gallons. 30 gallons of the tank is a blessing to some of the species. But only comet goldfishes need more space for one single fish.

They are large, as they can grow up to nine inches. On the other hand, putting a goldfish in a thirty-gallon tank is no harm to them.

A fancy goldfish can live up to 5 years in a 30-gallon tank. It is entirely safe for most species.

How big do goldfish get in a 30 gallon tank?

The record holder fish is about 18.7 inches long. But most of the species don’t get too larger. On average, a fish can get 10-12 inches when adults. The oranda goldfishes are the longest among all the species. For goldfish to become large, they need at least 30 gallons of water.

If more water or more space can be provided with proper food, these fish can go further than 8- 10 to 10-12 inches. Proper food and proper swimming capability give these omnivores to live healthily and stay fit.

What fish can live together with goldfish in 30 gallon tank?

You can put other companions to stay together in a 30 gallon tank with goldfish. Let’s get to know the different options you can opt for.


Two types of loaches can stay with goldfish in 30 gallons tank together. From them, loaches seem like small stingray, and they have these fishes like plecos.

Similarly, loaches like Borneo loaches, Sucker loaches, Butterfly loaches etc., loves to stay in cool water like goldfishes. So, these fishes can share space with a goldfish.


Several plecos are here, but Rubbernose and Bristlenose plecos can stay with a goldfish in a 30-gallon tank. Pleco fishes are commonly known to eat the slime coat of goldfishes.

But rubber-nose and bristle-nose plecos are relatively smaller in size and love to eat the wastes and algae. So, keeping these fishes in the tank with a goldfish will be good, as these fishes will keep the tank clean.

Longfin Rosy Barb:

Barbs are generally aggressive fish species. But longfin rosy barbs are pretty different than regular barb.

Longfin Rosy barb can stay in the cool water like goldfish. Both fishes can share a tank of 30 gallons. Female rosy barbs are recommended to be put inside the tank to share space with a goldfish.

How often do you need to change water and clean goldfish tank?

Goldfishes are so beautiful, but they are one of the most prominent wasters of the water. If the toxic level rises, the fish will gradually lose its beauty. When the fish tank water is not cleaned correctly, the pH drops and acidifies the water.

Fishes start to lose their energy and food to survive. For most fishes, the water must change every seven days. But as goldfishes are pretty dirty. The goldfish water tank needs to be changed every seven days.

What to put in a 30 gallon goldfish tank?

You can place dfferent aquirium oranments in your goldfish tank. Lets get to know them.


Goldfish love to play with pebbles. They love to restructure their place, and they love to put pebbles on their nose. Goldfish may choke on small pebbles, but it is recommended to put pebbles of a size that may not become a hazard to the goldfish.


Goldfishes have two hundred species all over the world. These fishes are from the tropical region, where the ponds and rivers are filled with small plants. Goldfishes love to search for food for themselves in those bushes.

If the plants are living plants, they may provide oxygen to the water. Moreover, goldfishes may nibble on specific plants.

Miniature Castle or Toys:

Goldfishes are good swimmers. If there are any miniature toys or castles inside the tank, they will not get bored. In the small castles, they might get inside and hide.

And they might make room for themselves to sleep at night. Goldfishes are diurnals, so they need good sleep at night.

Water Filter:

The most important thing that should go inside a tank with a goldfish is a water filter. As goldfish is one the best wasters, they need to have a water filter inside. It will help to remove any toxins from the filter.

Final thoughts

In a 30 gallons tank, most goldfishes can live without any problem. Even goldfishes stay in a couple of 30 gallons tanks. Rather than the Commet goldfishes, they need to have at least 50 gallons. Rest other goldfishes can live without any problem in a tank of 30 gallons.