I have a 22 gallon (100 litre) fish tank with 8 male guppies. I would like to add some betta fish, female or male, but I’m unsure if them two types of fish are ok to stay together or how many betta fish can be put into the 100 litre tank if I put my guppies into a smaller tank

  • 1
    In general you should have one male betta only and some females. I am not informed about if 100litre are enough to have two areas big enough to satisfy two male betta's territory behavior Commented Aug 11, 2022 at 22:38
  • 2
    No matter what size tank, two male bettas will find each other and fight. Commented Aug 13, 2022 at 15:21

4 Answers 4


You can have as may as you want, but not in the same aquarium. Two (or more) male betta's in one aquarium will surely find each other and fight to death. Just consider this: a male betta is always ready to even fight his own reflection in a mirror!!

Some sites claim that even betta females might have aggressive behavior, especially while they are having babies. That is why it is recommended to separate betta mothers to be alone in their own volume of water.

A betta male and a betta female can also become aggressive to each other, while they are together for mating. This is why in this case the aquarium needs to have a lot of hiding places for the female (plants, wood...).

The guppies will be fine, UNTIL the betta male will have a moment of confusion and will think that the guppies are also betta males (because of their large fins). That when the guppy family will start losing numbers.

Occasionally, male bettas will shows some signs of aggression towards "any" kind of fish - but this is related to the individual personality. Possible other causes would be boredom, or the male being ready to have a mate.

Betta males will usually not be aggressive to bottom dwellers, simply because they do not meet. Betta spends his life at the top of the water, while the bottom dwellers to the ... bottom (doh!).

Other than this, good luck with your decisions ;)


Only one male betta fish per tank! And I do not recommend putting bettas with guppies as they may nip each other's fins or get aggressive. As for female bettas, sometimes they are fine together, but sometimes they may fight and kill each other or get stressed. Not to say it hasn't successfully been done, but it may not be the best choice. Also, putting a male and a female betta together is possible, but you will need a larger tank and some experience at fishkeeping (which you very well may have, just something to consider.)

Overall, I recommend a different tankmate for your guppies, like tetras, danios, rasboras, or catfish. I hope this helps!

Here are some articles if you want them:
Top 12 Female Betta Tankmates
Can a Male and Female Betta Fish Live Together?

Thanks for your comment Allerleilurah! But please note that the point of these answers is so that the author can have a helpful, to-the-point summary of the requested information. The articles are good to have to back up your point if you are questioned, but they only have to be read through "if you want". They are not crucial to read. :) Thanks for understanding!

  • Welcome to pets.SE! The articles are crutial here, not only "if you want" :) Maybe you can also add one (if not mentioned in the others) for the statement "only one male per tank" Commented Feb 12, 2023 at 7:54
  • I am sorry I was not clear :) They are not crutial to read for any reader of this post yes. But they are crutial for you to mention, because sources are needed at this site :) Commented Feb 16, 2023 at 6:17

Two or more male bettas is not a good idea; similarly, male betta and male guppies together can also be slightly problematic (as they both are colourful and have longish fins). I found the reproduction rate of guppies to be quite overwhelming at times, so I would expect some losses, but not a complete eradication of guppy population by the betta.

  • The second part is more anecdotal than answering the question. Additional this site wants to have sources for given advice, because we handle living animals. Would you please edit you answer? Commented Aug 13, 2022 at 7:14

I advise you not to let them live together. Because male guppies are brightly colored ones with flowing tails. Both cause aggression and territorial instincts in bettas. Putting a male guppies and male bettas together will cause spelling trouble and most likely lead to the death of your guppies. So it's better to keep them separate. And if your size is 22 gallons then I think you can keep 4-5 betta fish is perfectly suitable.

  • 2
    Welcome to pets.SE! Would you please add some source, where your knowledge comes from? Expetience or book or website would fit :) Commented Nov 4, 2022 at 6:49
  • 1
    @NorrisBartoletti: your answer actually has 2 problems. 1. It is not guaranteed that the betta will attack the guppies. There might be a chance, but it is not guaranteed. I had a male betta with several guppies, and things were fine. I did not even have plants or ornaments at that time in the aquarium, and things were still fine. 2. "4-5 betta fish is perfectly suitable" wow! maybe if the betta are females. If the betta are males, you will need a lot of carnivore fishes there to eat all the resulting meat after the fight. And that would be a legendary fight !!
    – virolino
    Commented Nov 7, 2022 at 6:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.