Skip to Content

How Many Angelfish in a 20 Gallon Tank? (Explained)

When it comes to aquariums, angelfish are one of the most popular choices among fish enthusiasts. They feature a beautiful exterior appearance with a blend of some of the most vibrant colors.

Because angelfish are freshwater fish, they always contribute to the aesthetic appeal of our aquariums. They’re easy to handle if you equip them with the proper environment, which includes a decent tank and enough food.

Correct tank or aquarium conditions must be maintained to encourage the Angelfish’s healthy upbringing. This brings the issue of how many Angelfish can be housed in a 20 gallon tank.

Let’s have a more in-depth discussion about it and learn some intriguing facts about angelfish.

How many angelfish in a 20 gallon tank?

A 20 gallon tank is good for keeping one Angelfish. As Angelfish grow up to 8 to 12 inches on average, it is better to keep adequate swimming space for them in the tank. However, if you want to accommodate 2 angelfish, you will need a bigger tank with a higher gallon capacity.

The size of the tank may differ for different species. Let’s get to know about them.

Freshwater angelfish:

Freshwater Angelfish can live in a 20 gallon tank. However, a very important point to be noted here is that Angelfish are quite aggressive in nature.

That’s why it is very important to set the tank properly for freshwater Angelfish so that they are fully comfortable inside it. Maintaining the appropriate temperature and pH level is crucial in the tank where you will be keeping your Angelfish.

20 gallon is quite spacious for one freshwater Angelfish. Thus, it is highly recommended to keep just one Angelfish in a 20-gallon tank as it will allow the fish to have adequate swimming space.

Plant different aquatic plants inside your aquarium or tank so that your Angelfish does not get bored and can keep itself busy. These aquatic plants would also keep them distracted.

It is necessary to clean the tank every 2 days to maintain a clean environment inside the tank. Moreover, make sure to supply a healthy diet and an adequate amount of food to your Angelfish.

Angelfish tend to grow from 6 to 8 inches long. They tend to grow taller rather than being growing wider.

Therefore, make sure that the 20 gallon tank that you are buying for keeping your Angelfish is taller rather than being broader in terms of structure.

Can 2 angelfish live in a 20 gallon tank?

Yes, 2 Angelfish might live in a 20-gallon tank if the tank is taller and less wide. However, it would be quite difficult for them to live together in a 20-gallon tank as they would have very congested swimming space.

A 20 gallon tank is quite spacious for two fish. However, the scenario is a bit different in the case of Angelfish.

Angelfish may reach lengths of almost a foot. As a result, their bodies are gigantic, and when fully grown, they are usually quite tall in nature.

Thus, when two Angelfish are newborns, they may survive in a 20 gallon tank for a short time, but not when they are adults.

Angelfish are adapted to dwelling in wide areas by nature. As a result, as long as they are newborns, the area they live in will have little impact on them. They would, however, desire a large region to live in as they get older.

Therefore, even though 2 Angelfish may live in a 20 gallon tank, it is highly discouraged by the experts.

3 factors that determine the number of angelfish that can live in a 20 gallon tank

There are some facts that you need to know for determining the number of angelfishes in a tank. Let’s get to know about them.

Capacity of the tank:

The first and foremost factor that determines the number of Angelfish that can live in a 20 gallon tank is the capacity of the tank itself. Here, the capacity of the tank is 20 gallons.

In a 20 gallon tank, one Angelfish can easily be accommodated with adequate space. Thus, the capacity of the tank is one of the most important factors in determining the number of Angelfish that can live in a 20 gallon tank.

Growth of the Angelfish:

Another factor that determines the number of Angelfish in a 20 gallon tank is the growth of the Angelfish.

The Angelfish may grow to be over a foot long at times. As a result, they have gigantic bodies and, when fully mature, are usually fairly tall in nature.

Thus, their growth determines whether or not they will be able to live in a 20 gallon tank.

The Comfort of the Angelfish:

Angelfish require quite an amount of area to swim in. They may become quite unhappy if they don’t have enough space to swim.

If they do not have the environment they want to live in, they can become rather violent and aggressive. As a result, the comfort of the Angelfish is an important factor in determining how many of them can be kept in a 20 gallon tank.

Is 20 gallon tank too big for angelfish?

No, a 20 gallon tank is not too big for an Angelfish. Rather, a 20 gallon tank is the bare minimum size requirement for any Angelfish where they can be kept.

Angelfish require a minimum tank capacity of 20 gallons. However, because they thrive in tanks 10 gallons larger than the minimum size, it is best to keep them in a 30 gallon tank if at all possible.

Angelfish are territorial creatures who may also be aggressive. As a result, you could maintain just one Angelfish in a 20 gallon tank at a time. Keeping plants in an Angelfish tank is a fantastic way to keep them entertained and prevent boredom.

You can keep four Angelfish in the same tank at a time. However, this would necessitate a larger tank with a larger gallon capacity.

Moreover, to keep your Angelfish happy, make sure it has ample swimming space. A minimum of 20 gallon space is required for this.

What size tank do I need for 2 angelfish?

It is ideal to use either a 29 gallon or a 30 gallon tank for keeping two angelfish together.

Angelfish cannot survive in a small tank. They also prefer to dwell in huge areas, whether in freshwater or in aquariums.

They will be much more in harmony if they are kept in a location that is at least 10-gallons greater than the space they require for smooth, easy movement and optimal development.

When angelfish reach adulthood, they grow quite large in both length and width. When they are young, the 2 Angelfish may be housed in a 20 gallon tank. However, if they continue to grow to their full size, they will feel claustrophobic in that little space.

Another reason a 29 or 30 gallon tank is ideal for two Angelfish is that, due to their genetics, they grow exceptionally tall in nature. They measure 4 to 6 inches in width and 8 to 10 inches in height.

As a result, with such a huge and massive body, two Angelfish feel perfectly at ease roaming about a 29 or 30 gallon tank while still having enough swimming area.

What other fish can live with angelfish in 20 gallon tank?

To know what fish can you keep together with angelfish, check the list below.

Bristlenose Plecos:

Bristlenose Plecos are considered one of the ideal tank mates for Angelfish. Because the tanks where the Angelfish usually live need cleaning every 2 to 3 days.

But, Bristlenose Plecos are mostly plant eaters for which they feed on the algae. As a result, they play a significant role in keeping the tanks clean.

Dwarf Gourami:

Angelfish and Dwarf Gourami are eating buddies who feed on almost very similar diets, which include small insects, algae, flake foods, etc.

Even though they do not get into that many conflicts among themselves, the Angelfish might bully the Gourami for territorial issues.

As the Gourami are very peaceful and calm-natured, they don’t seem to protest much against the Angels. However, they make great partners when it comes to being tank mates.

Corydora Catfish:

Corydora catfish are great at maintaining communal relationships with other fish. That’s the reason why they are considered one of the most viable options for Angelfish as tank mates.

Because corydoras prefer to live in groups, it is strongly advised to keep at least 2 to 5 corydoras in the tank with the angelfish.


If you want to keep different color variations in your aquarium, then you can most definitely keep some hot orange and reddish-hued swordtails along with your Angelfish.

They are community fish who usually love to stay in groups. They are quite cheerful and notorious fishes who love to jump around the tank, keeping the surroundings all jolly and happy. Thus, they make great partners for the Angelfish.

Final Thoughts

One Angelfish may be kept in a 20 gallon aquarium. Angelfish may grow up to 8 to 12 inches long, so make sure there’s enough room in the tank for them to swim around. If you wish to keep two angelfish, though, you’ll need a larger tank with a greater gallon capacity.