What Types of Saltwater Fish Can Live in Community Tanks

Have you ever thought about whether fish can live together or not? As we all know, different species of fish possess different requirements and have various temperaments. Since that, do you know what types of saltwater fish can live in community tanks? If you do not know exactly, do not hurry, just read this article and you will get answers.

Content Table

What fish can go into a saltwater community tank?

To begin with, the community tank means that different creatures coexist in one aquarium. And we will cover some types of fish that can go into a saltwater community tank.




The Clownfish is one of the most popular saltwater fish. It is hardy and easy to keep. Besides, they are peaceful. The tank to keep the fish should not be less than 20 gallons. Clownfish are omnivorous. Furthermore, the accepted pH and water temperature respectively are 8.0-8.4 and 76-78℉. And it can grow up to 4 inches.

Royal Gramma

Royal Gramma

Royal Gramma

The Royal Gramma is hardy and peaceful. It likes low lighting levels and hiding in rocks, and it belongs to the bottom fish. Besides that, it is a carnivore and easy to keep. The tank to keep the fish should be 30 gallons at least. And they can grow up to 3 inches. On the other hand, the suitable water temperature for the fish is 73-80℉, and the pH is 8.0-8.5.

Firefish goby

Firefish goby

Firefish goby

The Firefish goby is long and thin. Besides, its body is light-colored and it is with a red, orange, or magenta tail. Its dorsal fin can defend against predators. Moreover, it is peaceful, calm, and non-confrontational, which makes it suitable for community tanks. Furthermore, it moves fast and likes hiding. And they can grow to 2–3 inches. The minimum tank size for the fish is 50 gallons. The fish requires a water temp of 72-80℉ and a pH of 8.1-8.4. And the fish are omnivorous. By the way, it is recommended to keep one Firefish goby in each tank, and the clownfish and gobies are ideal tank mates for it.




Saltwater fish Tang is a peaceful one. Although they sometimes become aggressive with other tang species, they are suitable for saltwater community tanks. Besides, they are herbivores and can grow to 6–24 inches. Tanks over 70 gallons are ideal for them. The ideal water temp is 72-78℉, and the suitable pH is 8.1-8.4.

Banggai cardinalfish

Banggai cardinalfish

Banggai cardinalfish

The Banggai cardinalfish possesses long and flowing fins, giant eyes, white spots, vertical black stripes, and silver sides. It is peaceful and can get along well with other non-aggressive community fish. Besides, it requires a water temperature of 78-82℉and a pH of 7.8-8.2. Moreover, the minimum tank size should be 30 gallons. Furthermore, they can grow up to 3 inches and live for 5 years.

How many fish can be put in a community tank?

Balance is critically important for fish aquariums. If overstocked, it will be harmful to fish. So, how many fish can be put in a community tank?

In freshwater aquariums, we can take a reference of one rule – one inch of fish for more than one gallon of water. Although there are different requirements for different fish, this rule can ensure room for fish. For example, if you have an 8 gallon tank, and you want to keep bettas in it. The average size of adult bettas is 2.5 inches. Considering the space for plants or fish tank decorations, it is better to keep 1-2 of them in your 8-gallon tank.

However, in saltwater aquariums, a general guideline is one inch of fish for more than 2–3 gallons of water. However, it is essential to the specific needs of each fish species. Take Tang fish as an example, they need a minimum tank size of at least 75 gallons.

How many fish can be put in a 20-gallon community tank?

Generally speaking, you can keep 2-5 for 2-inch fish, or 2-6 for 1-inch fish in a 20-gallon tank. By the way, peaceful fish are ideal for a 20-gallon community tank. Tetras, guppies, and rasboras are great options for you. For a tetra community tank, it is recommended to keep 5 glow light tetras, 5 neon tetras, and 3 cherry shrimp in the tank. And if you want to know more about how many fish you can keep in a 20-gallon tank, you can read another article – How Many Fish in a 20 Gallon Tank.

On the contrary, 20-gallon is relatively small for saltwater fish. Commonly, you can only hold a few small and peaceful saltwater fish. For instance, 1-2 small gobies or clownfish.

How many fish can be put in a 40-gallon community tank?

40-gallon tanks are the ideal size for beginners, which provides many stocking options. A 40-gallon tank can keep 10-20 small fish, such as tetras, or 1-2 medium-sized fish. If it is a saltwater tank, it can keep 5-6 small fish and corals.

In summary, there are factors you should notice when you determine the number of fish in your tanks, including the size of fish and tank, water quality and oxygenation, the filtration of your tank, and the aggressive levels of fish you stock. By the way, you should research the requirements before you introduce them into your tank.

Community tank suggestions

There are suggestions for setting up community tanks. You should notice the following factors, including the species of fish, the tank size and the number of fish, the distribution of fish, and food.

The species of fish

There are cold-water fish, tropical fish, freshwater fish, and saltwater fish. Some fish prefer alkaline water, while some other fish like acidic water, but the aquarium only with one kind of water parameter. So it is better to keep fish with similar water requirements in the community tank. You should research the ideal temperature, pH levels, hardness, and something like that in advance.

The tank size and the number of fish

You should choose a tank as large as possible. A small tank may cause crowded and narrow the space of fish, then they may fight for space for movement. Because the fish require moving room, if your tank has a high density of fish, the fish will have less space to move accordingly. In such a case, the fish may get sick easily.

The distribution of fish

Generally speaking, there are top fish, middle fish, and bottom fish. You can choose fish in different distributions to avoid crowding. For example, the goldfish are the middle fish, and the guppies are the top fish.


Fish will fight with each other for the sake of food shortage. You should ensure enough food to meet their requirements, if so, fish will fight less, and the injuries will be less too. Since then, the possibility they get sick will reduce. By the way, food that may lead to fights between large fish should be avoided at the primary time, such as centipedes. On the other hand, you should also pay attention to the speed of eating. Some fish eat slowly, while others eat quickly. If you keep the two together, some will be overfed, but some will not get enough.


Congratulations! You have enjoyed reading and got answers, right? By the way, there is one tip for you. You should avoid keeping aggressive fish together, or they may fight with each other, and then get injured. Besides that, you should be careful when you choose tank mates for aggressive ones. Furthermore, if you notice there are sick fish in your tank, you should treat them as soon as possible. It is better to keep the sick one in a quarantined tank, or it may infect other fish.

Finally, thanks for your reading!

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Comments (2)

  1. The first part of this, it is talking about saltwater community fish. Then when you get to how many fish can you put in a aquarium, you switch to talking about fresh water fish. There is a difference on the number of saltwater fish per gallon than it is how many fresh water fish per gallon.

    Sep 3, 2023 Reply
    • Hello, Darlene. Thanks for your comment. Now, we have made the corresponding modifications to the content. Feel free to share your ideas with hygger. Wishing you a pleasant life.

      hygger team

      Sep 4, 2023 Reply

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