How Many Goldfish in a 50 and 55 Gallon Tank?

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When stocking a goldfish tank, one of the most important questions is how many fish the tank can comfortably accommodate. Though a general rule of thumb is that each fish needs at least 10 gallons of water, goldfish are particularly messy eaters and produce a lot of waste. A 50-55 gallon tank is a good size for a small group of goldfish, allowing them plenty of space to grow and swim.

In this article, we’ll discuss how many goldfish you can keep in a 50 or 55-gallon tank. We’ll also provide tips for maintaining a healthy and happy goldfish community. 

How Much Water Do Goldfish Need?

An excellent way to assess how many fish your tank can accommodate is by using the gallon per inch method. This rule states that every inch of goldfish should be housed in at least 1 gallon of water. So, for example, a 6-inch goldfish needs at least 6 gallons of water. This rule outlines the minimum amount of water each goldfish needs for a healthy environment.

The tank size is not the only factor determining how many fish it can accommodate. The type of goldfish you have, and how often you perform water changes, also play a role. Generally, however, a larger tank would be better for goldfish since they are such messy eaters. They produce a lot of waste, quickly polluting the water and leading to unhealthy conditions.

When in doubt, it’s always better to err on the side of caution and provide more space rather than less.

How Many Goldfish Can I Put in a 50 or 55-Gallon Tank?

Based on the gallons of water per inch rule, a 50-gallon tank could accommodate 5 goldfish that are each 10 inches long. You could probably fit more fish in the tank if you have smaller goldfish. For example, 10 goldfish each 5 inches long would also be appropriate for a 50-gallon tank.

Keep in mind, though, that the average size for goldfish is around 6-8 inches. So, stocking a 50-gallon tank with 10 five-inch goldfish leaves little room for error and growth. It’s always best to assume that your goldfish will grow to their full size and plan accordingly.

Therefore, we recommend stocking 5 goldfish in a 50 or 55-gallon tank. This will allow each fish plenty of room to grow and swim without overcrowding the tank.

What Happens When A Tank Is Overcrowded?

We’ve all seen those images of fish tanks crammed full of fish. While it may seem like the fish are doing just fine, overcrowding is one of the goldfish’s greatest detractors from life quality. When a tank is too small, the fish don’t have enough space to swim and explore.

Goldfish are intelligent, active creatures that require plenty of swimming space. A small tank inhibits their movement and can lead to health problems such as swim bladder disease. In addition, an overcrowded tank is more likely to experience water quality issues such as ammonia spikes. Ammonia is a by-product of fish waste and can be toxic to goldfish in high concentrations.

Yet another problem with an overcrowded tank is that it can lead to stunted growth. Their growth is slowed when goldfish don’t have enough room to swim. This is because they don’t get the exercise they need to develop properly.

To provide your fish with a stress-free environment, it’s best to give them plenty of space. That way, they can swim, explore, and grow to their full potential.

What Affects The Number of Goldfish You Can Keep In A Tank?

Previously, we stated that a 50 or 55-gallon tank could accommodate 5 goldfish. This is a good general rule, but a few factors could affect the number of fish you can keep in your tank.

Goldfish Type

goldfish school

The type of goldfish you have can affect how many fish you can keep in your tank. For example, fancy goldfish are usually smaller than common goldfish. As a result, you could probably keep more fancy goldfish in a 50 and 55-gallon water tank than common goldfish.

However, since tank size requirements are based on inches of fish, the type of goldfish isn’t as important as the size. So, if you have small goldfish that are only 5 inches long, you could technically keep 10 fish in a 50-gallon tank. But, again, providing more space rather than less is always better.

Water Quality

Water quality rests upon two important factors: the size of your tank and how often you perform water changes. A larger tank is always better since there’s more water to dilute the waste produced by your goldfish. In addition, performing water changes on a regular basis is crucial for maintaining water quality.

Something else that can alleviate issues relating to poor water quality is effective filtration. Whether you have a 50 to 55-gallon tank or a larger pond, a good filter will help to keep the water clean and clear. That way, you can be sure your goldfish are living in a healthy environment.

Tank Decor

Fish Tank Plants Decor

It’s tempting to introduce new items from time to time to spruce up your goldfish tank. However, you need to be careful when adding decor to your tank. Too many items can crowd your tank setup and make it difficult for your fish to swim.

Of course, a lot of this depends on the shape of your tank. Rectangular tanks have a larger surface area, which means you can add more decor without overcrowding the tank. However, cube-shaped tanks and tall tanks have less surface area. As a result, you’ll need to be more selective when it comes to decorating these tanks.

In general, it’s best to use the space in your tank by adding items that replicate the natural habitat of your fish. In other words, try to create a setup that includes both open swimming areas and hiding spots. That way, your fish can explore their environment and feel secure at the same time. After all, don’t we all want a delightful tank setup that’s also comfortable for our pets?

Tank Mates

Last but not least, a healthy goldfish tank should consider your fish’s tank mates. If you’re planning on keeping goldfish with other fish species, be sure to do your research ahead of time. If you plan on housing your goldfish with larger tank mates, you may need a bigger tank to accommodate everyone. This means that a 50-55 gallon tank will only be able to accommodate a smaller number of goldfish if you’re also keeping other fish species in the same tank.

Celestial Eye or Stargazing Goldfish
Image Source:

Although having to keep a smaller number of goldfish may seem like a big trade-off, it’s better for your fish’s health. Many goldfish with tank mates thrive because they have the company of other fish. In fact, some goldfish owners report that their fish become more active and playful when they’re kept with other fish.

The Takeaway

So, there you have it! These are some of the things to consider when deciding how many goldfish to keep in a 50 to 55-gallon tank. Remember, it’s always better to provide more space for your fish rather than less. In addition, be sure to consider the other factors that can affect the health of your fish, such as water quality and tank mates. By considering all of these things, you can be sure that your goldfish will have everything they need to thrive.

Did you find this article helpful? If so, please share it with your friends! And, if you have any questions or comments, please leave them below. Happy fishkeeping! 

Wanda is a second-generation aquarist from the sunny tropics of Malaysia. She has been helping her father with his freshwater tanks since she was a toddler, and has fallen in love with the hobby ever since. A perpetual nomad, Wanda does her best to integrate fish-keeping with her lifestyle, and has taken care of fish in three different continents. She loves how it provides a nice break from the hustle and bustle of life.

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