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How Many Goldfish in a 29 Gallon Tank? (Quick Answers)

For beginner aquarists goldfish are a great choice. They are eye-catching and come in different colors which attracts aquarists to have goldfish. If they get proper accommodations and care they live up to ten years. 

However, their lifespan can decrease if they don’t get proper maintenance and space.

How many goldfish in a 29 gallon tank?

A goldfish can grow up to eight inches long and require a 4 feet wider tank to live peacefully which is close enough to 29 gallons. So, in a 29 gallon tank, one goldfish will be ideally fit. If added more fishes in it, they’ll find difficulties to breath which will result in reducing their lifespan.

It’s important to get a tank that’s the right size for goldfish so that they can live a longer, healthier life and grow to their full potential. A goldfish requires a 4 feet wider tank where it can live happily. 

However, a 29-gallon tank can hold nearly 109 liters of water which is also pretty comfortable for goldfish. But you can put only one common goldfish in a 29 gallon tank.

A 29 gallon tank will provide enough swimming space for a goldfish. Smaller than a 29 gallon tank is usually insufficient for them, as they grow large and produce waste. Goldfish grow quickly and become enormous, and they are excessively active. 

Thus, one goldfish is ideal for a 29-gallon tank. However, several other factors have a role in attracting goldfish to a tank, such as the filtration system, which should be ten times the tank volume, especially for fancy goldfish. 

Because they are a cold-water species, they need a comfortable temperature. Temperatures of 18 to 20 degrees centigrade are ideal for them. They will have difficulty receiving oxygen if they do not have adequate space, resulting in a reduced lifespan. 

Also, keep a watch on the nitrate level in the tank; it should not exceed 40, and anything less than that is desirable for their growth to avoid being stunted. 

With adequate care, one goldfish can survive in a 29-gallon tank. When goldfish are kept in small tanks or with more than one fish in a 29-gallon tank, they release hormones that can restrict their growth. 

If kept in good condition, one goldfish in a 29 gallon tank would be in the best possible environment.

How many of these goldfish can fit in a 29 gallon tank?

The growth, health, and maintenance of  goldfish are all affected by tank size. Some goldfish varieties grow quickly and are very active swimmers; their sizes range from twelve to fourteen inches, and they require a huge gallon tank of fifty gallons per fish, such as the comet goldfish. 

Some, like the fancy and fantail goldfish, are small, with six to eight niches, and may easily accommodate a goldfish in a 29-gallon tank.  

A properly sized tank will extend the lifespan even further. The larger the water tank, the easier it will be to keep the goldfish healthy. Most of the fancy and fantail goldfish use the upper and structured parts of the 29-gallon tank, which has an open space on top. 

It is simple to clean all the waste products that goldfish produce with a 29-gallon tank. Not only does tank size matter, but a powerful filter that can filter on a regular basis is also required for their healthy growth. 

Comet goldfish, on the other hand, cannot live in little 29-gallon tanks because they grow quickly and want more water to live in. Therefore, they demand a minimum of a fifty-gallon tank, which is ideal for them and also makes them easier to manage. 

Fancy goldfish: 

One fancy goldfish is preferred for installation in 29 gallon tanks since they are medium in size and may grow up to six or eight inches in length, and the size is ideal for them. 

They must be well maintained since poisonous enzymes released into the water may have an effect on them. 

Thus, tanks smaller than 29 gallons are not advised for fancy goldfish because a contaminated tank with insufficient oxygen may shorten their lifespan. 

More than one fancy goldfish in a 29-gallon aquarium will produce more waste and make it more difficult to keep them alive.  

Fantail goldfish: 

Fantail goldfish are restless goldfish that are best suited to a 29-gallon aquarium. Fantails require a lot of water to thrive, and a 29-gallon can hold around 109 liters of water that is pretty good for them. 

They also require strong water filtration on a weekly basis because they produce more waste. 

Comet goldfish: 

Comet goldfish do not fit in a 29-gallon tank; they require a larger tank, usually a 50-gallon. Comet goldfish are larger than regular goldfish. In general, comet goldfish can grow up to two feet in length, so a 29-gallon aquarium will not be enough for them.

They might become sick if placed in a 29-gallon tank. 

You’ll need additional tank room if you have more than one comet goldfish; otherwise, upkeep will be challenging because they’re active swimmers who thrive restlessly everywhere and produce significant amounts of hazardous waste. 

It’s possible that disease could spread, and a lack of oxygen will put them in danger, requiring the addition of a fifty-gallon tank.

Is a 29 tank good for goldfish?

There are varieties of goldfish and their length differs also. They normally grow up to 8 inches if they find proper accommodations and care. However, common fancy goldfishes grow 4 inches long and require huge space. 

They are active swimmers and grow very quickly. A 29 gallon tank is quite convenient for goldfish but you can’t add more than one goldfish into it. One 4 to 5 inch goldfish can live comfortably in a 29 gallon tank. 

However, if they grow more than 6 inches they might need more space or can have a lack of oxygen and fall sick. 

Can the two goldfish live in 29 gallon tank?

A 29 gallon tank is not suitable enough for two goldfish. A 3 inch goldfish requires 4 feet wider space to live and swim happily that is close enough to 30 gallons. 

However, you can keep one goldfish in it but two goldfish in this size of tank will not be an ideal choice as they grow large and produce a lot of waste. 

Is a 29 gallon tank big enough for 3 goldfish?

For 3 goldfish, a 29 gallon tank is very small. Goldfish grow very quickly and a minimum 30 gallon is necessary for an adult goldfish. 

The right size is necessary for their longer and healthier life otherwise the goldfish will have adequate space, find difficulties to breath and receive oxygen which will result in reducing their lifespan. In a 29 gallon tank, only one goldfish will be suitable.

What fish can you put with goldfish in a 29 gallon tank?

A common goldfish that can grow up to 6–8 inches requires a minimum 30 gallon tank. However, 29 gallon can also work well but while choosing tank mates and decorating it with other aquarium gadgets you have to be careful as they will shorten the space for them to swim. 

For 4 inches or bigger goldfishes, you shouldn’t add too many teammates, rather can add some tiny plants. However, if your goldfish is below 3 inches you can add some mates into the tank like: 


Glofish are very eye-catching, have a colorful body that you can put in your 29 gallon tank. They can grow up to 2.5 inches and for a 29 gallon tank you can keep 3-4 baby goldfishes. 

However, they’ll need a larger tank when they grow bigger and you’ll need to upgrade the size to a 40- to 55-gallon tank.


Tetra’s are tiny fishes that grow 1.5 inches to 2 inches, come in different colors and are suitable for small tanks. They are peaceful and calm in nature and 2-3 tetras can be good teammates with goldfish in a 29 gallon tank. 

Hatchet fish: 

Hatchet fish are also a great choice for a 29 gallon tank as they grow small, not more than 2 ½ and suitable for nano tanks. You can put 3-4 baby hatchet fish along with a 2 inch goldfish.


You can add one or maximum two guppies in your 29 gallon tank with a maximum 3 inches goldfish. They are a great choice as they grow not more than 2 inches. 


If your tank has a filter and heater you can add some bettas which are tiny colorful, long-finned fishes that’ll leave peacefully with goldfish. 

Final thoughts

To have a longer, healthy life, the right size of tank is necessary for goldfish. As goldfish are active swimmers and grow rapidly, they need larger space to swim and breathe. A 29 gallon tank is convenient for one goldfish but if more goldfish are added, they will feel suffocation and fall sick.