How Many Female Bettas in a 20-Gallon Tank? [Expert Aquarists Suggestion]

Bettas are known to be loners by nature. Yet, at times, they seem to enjoy the company of their own kind. Although the males are always territorial and often fight with one another, the females tend to get along relatively well. And a 20-gallon tank is just about perfect to house a few of them.

But how many female bettas in a 20-gallon tank can you keep safely? Generally, it’s okay to keep five to six female bettas in a 20-gallon tank without problems, however, several factors need to be taken into account. The key is providing enough hiding spots in the tank to reduce aggression.

Let’s explore the considerations when deciding how many female bettas to keep in a 20-gallon tank, and what setup is most effective for everyone.

How Many Female Bettas in a 20-Gallon Tank?

As we mentioned, you can typically keep five to six female bettas in a 20-gallon tank without any problems. Of course, there are a few things you need to take into account, such as the size of your fish and the number of hiding spots in the tank. Let’s get into more detail.

The Size of the Bettas

The size of the bettas is an important factor to consider when determining how many fish you can keep in a 20-gallon tank. Bettas are usually no longer than 3 inches, so they don’t need a ton of space.

But, if you have five or six large bettas, they’re going to need more space to swim with reduced aggression.

As a rule of thumb, each 2-3-inch betta needs about 3-5 gallons of water. So, if you have a 20-gallon tank, it can typically hold five to six female bettas.

The Number of Hiding Spots

It’s vital to consider how many hiding places you have in your tank. As we mentioned before, bettas are known to be aggressive, and they need plenty of places to hide to cope with stress.

A 20-gallon tank should have at least five to six hiding spots for each of the fish. If you have more bettas, you’ll need more hiding spots. The best way to provide hiding spots is to use live plants or decorations that create plenty of nooks and crannies.

Bettas prefer to mark their own territory, so it’s important to give them plenty of space to do so. If you have too many fish in a small tank, they’re going to start fighting for territory, which can lead to stress and disease.

Dividers

If you want to keep more than six female bettas in a 20-gallon tank, you can use dividers to give each fish its own space. Dividers are especially useful if you have male and female bettas in the same tank.

Keep in mind that dividers aren’t always 100% effective. Bettas can still see and smell each other, so they may still become stressed. If you do use dividers, make sure to provide plenty of plant life and hiding spots to reduce aggression.

Also, dividers in a tight space limit each fish’s swimming area, so you need to be careful not to overcrowd the tank.

Water Temperature

Another important factor to consider is the water temperature. Bettas are tropical fish, so they prefer warm water. A 20-gallon tank should be heated to 75-78 degrees Fahrenheit for 5-6 fish.

You can use a heater to maintain the water temperature or keep the tank in a warm room. If you live in a cold climate, it’s best to use a heater to keep the water warm enough for the fish. Nevertheless, if you don’t have a heater you can put warm water in the tank to control the temperature.

The more fish you put in a 20-gallon tank, the more crucial it is to maintain the correct water temperature. This is because the temperature will fluctuate constantly with more fish exuding waste and calories constantly.

Maintenance Frequency

One last thing to consider is the frequency of maintenance. A 20-gallon tank is going to need more frequent cleaning than a larger tank because it’s more likely to become polluted.

In general, you should do a 25% water change once a week and a 50% water change every two weeks. Of course, you may need to do more frequent water changes if the tank becomes dirty more quickly.

So, how does this affect the number of fish you can keep in a 20-gallon tank?

Well, the more fish you have, the more waste they produce, and the faster the tank will become polluted. This means you’ll need to do water changes more often, which can be time-consuming.

If you don’t want to spend a lot of time maintaining your tank, it’s best to stick with three or four fish.

Mistakes to Avoid for a Successful Setup of a 20-Gallon Tank for Bettas

Now that you know all the factors to consider, let’s take a look at some of the most common mistakes people make when keeping female bettas in a 20-gallon tank.

Not Enough Hiding Spots

As we mentioned before, bettas are known to be aggressive, and they need plenty of places to hide to reduce stress. A 20-gallon tank should have at least five to six hiding spots for the fish. If you have more bettas, you’ll need more hiding spots.

Decorating with Only Fake Plants

Bettas prefer live plants because they provide hiding spots and help to oxygenate the water. Live plants can, of course, be expensive, and they may not be available in your area.

Yet, you must have some plants in the tank because bettas need natural hiding spots with plenty of nooks and the natural aquatic feel for a relaxing environment. However, you must be also careful about the toxic plants for Betta fish as they could do more harm than assist in maintaining the tank ecosystem.

Overstocking the Tank

Bettas need a lot of space to swim, so it’s important not to overcrowd the tank. A 20-gallon tank can comfortably accommodate five to six female bettas. If you have more fish, they’re going to start fighting for territory, produce more waste, and the water quality will suffer.

Not Maintaining the Water Quality

As aforementioned, a 20-gallon tank is more likely to become polluted than a larger tank. This is why it’s so essential to do regular water changes (ideally, at least once a week), and maintain the correct pH (6.5-7.5), hardness (3-4 DGH), nitrate level (less than 20 ppm), and temperature (75-78 degrees Fahrenheit).

Placing a Male with Female

And the gravest mistake of all is placing a male betta with females. When you do this, the male will become agitated, and he may start to attack the females. If you really want to breed your bettas, you’ll need to set up a separate breeding tank. You can check one of our articles on this beta fish mating without killing each other.

Frequently Asked Questions

Down below, we have answered some of the most frequently asked questions about keeping female bettas in a 20-gallon tank.

Can you set up a betta sorority in a 20-gallon tank?

Betta sorority means having a group of female bettas in the same tank. While it’s possible to do this in a 20-gallon tank, it’s recommended to weigh the potential benefits against the risks before choosing the number. Our write-up above provides more details about these considerations.

Can you keep other fish with female bettas in a 20-gallon tank?

Yes, you can keep other fish with female bettas in a 20-gallon tank, ideally, ember or neon tetras, as they are peaceful community fish that get along well with bettas. Two or three female guppies, platies, and mollies are also considered suitable tank mates for bettas.

Is a 20-gallon tank spacious enough for bettas?

Bettas need a lot of space to swim, and a 20-gallon tank is actually on the smaller side. Ideally, you should have a 30-gallon tank for housing multiple bettas, but a 20-gallon tank will suffice if you’re only keeping five or six of them.

Do female bettas need a heater in a 20-gallon tank?

Female bettas need a heater in their tank because they are tropical fish that come from waters with a temperature of 75-80 degrees Fahrenheit. So, a 20-gallon tank should have a heater that can raise the temperature of the water to at least 75 degrees.

Do female bettas need a filter in a 20-gallon tank?

It’s recommended that you have a filter in your 20-gallon tank because it will help to keep the water clean and free of toxins. Bettas are sensitive to ammonia and nitrites, so a filter will help to remove these harmful chemicals from the water.

Conclusion

We hope that this article has helped you to better understand the requirements for keeping female bettas in a 20-gallon tank. In sum, as long as there is enough room for each betta to get away from the others, five to six females can live in a 20-gallon tank without problems.

Even though a 20-gallon tank may seem like a lot of work, the effort is definitely worth it once your bettas can swim around freely. And if you think the plants are hard to find or expensive, some java fern for each fish should suffice. So, don’t be discouraged, and good luck.