How Many Betta Fish in a Tank? (Males & Females in 1-75 Gallons)

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Growing multiple bettas in one tank can be both challenging and exciting. One of the most important things to consider before setting up a new tank is how many bettas can live together in your freshwater fish tank. After years of experiment, I am reading to share my conclusions on this topic.

One male betta fish requires 20 gallons of water, while female bettas require 5 gallons. For example, 40-gallon tanks can hold two males and eight females. That is because male bettas are aggressive and territorial, as opposed to their female counterparts.

As we proceed, I will show you exactly how many bettas you can grow in a fish tank while considering your tank’s size and the fish’s gender. Then, I will share seven tips I suggest you follow to ensure that your bettas can live happily side by side.

How Many Bettas Can I Grow in a Tank?

Small-Sized Fish Tanks:

  • 1-Gallon tanks can hold 0 betta fish.
  • 2-Gallon tanks can hold 0 betta fish.
  • 2.5-Gallon tanks can hold 0 betta fish.
  • 3-Gallon tanks can hold 0 betta fish.
  • 3.5-Gallon tanks can hold 0 betta fish.
  • 5-Gallon tanks can hold one male and one female.
  • 6-Gallon tanks can hold one male and one female.
  • 6.5-Gallon tanks can hold one male and one female.
  • 7-Gallon tanks can hold one male and one female.

Medium-Sized Fish Tanks:

  • 10-Gallon tanks can hold one male and two females.
  • 15-Gallon tanks can hold one male and three females.
  • 20-Gallon tanks can hold one male and four females.
  • 29-Gallon tanks can hold one male and five females.
  • 30-Gallon tanks can hold one male and six females.

Large-Sized Fish Tanks:

  • 36-Gallon tanks can hold one male and seven females.
  • 40-Gallon tanks can hold two males and eight females.
  • 55-Gallon tanks can hold two males and eleven females.
  • 60-Gallon tanks can hold three males and twelve females.
  • 75-Gallon tanks can hold three males and fifteen females.

Bettas are very territorial, especially males, so keeping more than one male in a tank will lead to fighting. Some people choose to keep multiple males in a single tank, but the males may become stressed from being kept close to each other. On the other hand, the females have no such problems.

Bettas can live together peacefully if they have an adequate amount of territory. For example, 40-gallon tanks can hold two males and eight females. However, the amount of fish in a tank can vary widely depending on the size of the tank.

The presence of hiding spots also matters. Tanks that feature cave-like spots can be used to house multiple bettas. The smallest caves have several hiding spots, while the most spacious ones have numerous caves that provide adequate space for multiple betta fish.

However, tanks that get overcrowded will get the opposite results. The bettas will be stressed as they cannot find a place to hide. Also, they will encounter each other more frequently. This way, fights are more likely to occur.

It’s always good to have more than one female in a tank. That will prevent the males from competing with each other. As a rule of thumb, I suggest picking five females for every male betta fish.

  • Here is an excellent Youtube video that shows how female bettas get along in one tank:

Can Two Male Bettas be in the Same Tank?

Two betta fish can be in the same tank as long as it features more than 40 gallons of water. Smaller tanks will not be able to accommodate two male bettas, mainly due to their aggressive and territorial characteristics. 

As was mentioned earlier, it is a different case when it comes to female betta fish. You can easily grow two of those in tanks that are merely 10 gallons. The shape of the tank also matters. Tanks that are wider than taller are more recommended since the fish can swim horizontally without meeting each other.

  • Here is a Youtube video that shows that two male betta fish usually don’t get along in small tanks:

How to Add Several Bettas to a Single Fish Tank?

If you decide to grow several bettas together, you must add them gradually. This is because different individuals will have different personalities. For example, one betta might get along with you while another would not. So instead of adding them all at once, you should add them one at a time.

There is no exact method to this, though. The best thing to do is to try and see how each individual behaves with the other fish in the tank. If there are any signs of negative behavior, you should remove it immediately until the situation calms down.

It may also be a good idea to get bettas that already grew up together in the store. The probability of them fighting with each other is less significant if they are already familiar with each other.

If you have a spare tank, get a few bettas and split the tank in half so that each individual can have his or her own territory. After a week or two, remove the divider and see how the fish behave. It is more likely that they will get along this way.

How to Set up a Multiple Bettas Tank

If you wish to grow multiple bettas in the same tank, the first step would be to decide how many bettas you should get. This is where the information at the beginning of this article becomes useful.

However, there are a few additional steps you should take to set up a multiple bettas tank. They are all meant to mitigate stress and create a comfortable environment for your betta fish:

1. Setting the Right Water Parameters

The essential water parameters for betta fish are pH, ammonia, nitrates, nitrites, and temperature. When all of these are correct, you can look for additional ones like water hardness and chloramine.

Generally, the ideal pH for bettas falls between 6.8 and 7.5.[1] If it is lower than that, the water is too acidic for this particular fish. The ammonia, nitrates, and nitrites should be around 0 ppm. If they are above that, they shouldn’t exceed 0.5 ppm.[2]

To measure the pH, ammonia, nitrates, and nitrites levels, I personally use the API Aquarium Test Kit (link to Amazon). After testing dozens of kits, I have concluded that this is the best one. It is the most accurate and easy to use. 

If you find the water too acidic, you probably need to perform more regular water changes. As a rule of thumb, I suggest replacing 15 to 20 percent of the water weekly. This way, you won’t stress your fish by changing their environment too abruptly.

As for the temperature, it should fall between 75-80 degrees Fahrenheit.[3] Water that is too hot will stress your betta and won’t hold oxygen properly. On the other hand, too cold water will compromise the fish’s metabolism.

It is also crucial that the temperature remains stable. That is why I use the Cobalt Aquatics Flat Neo-Therm Heater (link to Amazon), which I also reviewed here. It delivers a consistent flow of accurate temperature and allows you to set the desired level.

2. Creating Hiding Spots

Betta fish thrive when they have hiding spots. Most people add caves and plants into their tanks. However, I recommend incorporating both of those. Caves are large enough to hide bettas and allow them to rest without any risk of getting spotted by other fish or predators.

Plants are also good because they increase the biodiversity of your tank and give the fish a place to hide. But you need to make sure they don’t block the tank’s flow. Otherwise, it will stress your betta fish and sometimes prevent it from eating. If you will be using gravel, it is best to put a thin layer of rocks or pebbles.

3. Feeding Your Bettas Properly

If you have decided to get multiple bettas, then it is advisable to consider nutrition. In a nutshell, you need to provide the fish with a pellet-based diet. Preferably one that is made of high-quality ingredients and is offered once or twice a day.[4]

Please note that you should put two to four pellets for each betta fish. So, for example, if you grow three females and one male (a total of four betta fish), you should give them between 8 to 16 pellets.

Multiple bettas will also enjoy snacking on vegetables and live foods. However, the pellets should be their primary source of nutrition. There are three types of pellets that you can use: freeze-dried, frozen, and frozen freeze-dried. I personally use the TetraBetta Floating Mini Pellets (link to Amazon).

4. Providing Enough Oxygen

Tanks that contain multiple bettas may require more oxygen. In this case, you will need to provide them with a fish tank aeration system. Stagnant water will contain less oxygen and may even promote the growth of ammonia, compromising the fish’s ability to breathe.

To increase the oxygen in my tank, I use the Hygger Aquarium Air Stone Kit (link to Amazon). I love this one because it is affordable and easy to use. All you have to do is connect the different parts and place the device in the middle of your tank.

5. Choosing the Right Tankmates

If it is your first time growing multiple betta fish, I suggest picking no other tankmates. They will only compete with your bettas for territory and may raise hostility. But if you wish to grow a few other species, the best tankmates would be snails, clams, and shrimps.

It is best to avoid other fish species because most of them don’t get along with bettas. Also, some of these fish may not make it since bettas are aggressive by nature. Yet, some species that may live peacefully with bettas include Kuhli Loaches, Ember Tetras, Cory Catfish, and Harlequin Rasboras.[5]

6. Cleaning the Tank Regularly

Waste and debris quickly build up in tanks that house several bettas and other fish species. Therefore, you need to regularly clean the tank’s surface, the filter, and any water outlets so that the microorganisms may not develop.

Doing a 15-20 percent water change every week is also a good idea. It will keep your tank cleaner while still providing enough oxygen to your fish. In addition, it will prevent your water from getting stagnated and maintain your pH level at a constant point.

I also suggest vacuuming a substrate once a month. For my aquarium, I got the Hygger Aquarium Gravel Cleaner (link to Amazon). I really like this one because it works manually, so you don’t accidentally vacuum things that are supposed to stay in your tank.

7. Ensuring Proper Cycling

A tank that holds multiple bettas needs to be appropriately cycled. This is due to nitrates and ammonia, which can result in extremely high levels of these compounds. One way to make sure that this doesn’t happen is by adding nitrifying bacteria into your tank. 

This way, they will convert these dangerous compounds into substances that bettas can tolerate. For that purpose, I use the Tetra SafeStart Plus to Cycle New Aquariums (link to Amazon), although there are numerous similar products out there.

As was mentioned earlier, it is vital to perform regular maintenance. However, if your tank is relatively new, avoid cleaning the filter’s media. This part usually contains good bacteria that are necessary to aquarium fish.

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Conclusions

I hope this article has helped you out. It is definitely not a complete guide, but it should provide you with enough information to start growing more than one betta fish at a time. There is tons of information on the internet, so you may use it in combination with this article to achieve a better result. 

If you are looking for a short answer, female bettas are more flexible when it comes to growing multiple betta fish in a single tank, and you should adjust the water parameters to make them live peacefully. Start by adjusting the pH, temperature, and ammonia levels.

References

  1. https://www.aqueon.com/information/care-sheets/betta
  2. http://aquariumkids.org/betta-care-sheet/
  3. https://home.adelphi.edu/~ve21375/Betta%20Fish%20Care.html
  4. https://pets.webmd.com/what-do-betta-fish-eat
  5. https://www.aquariumcoop.com/blogs/aquarium/betta-tank-mates

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