Bettas and Mollies Living Together: (Tips and Pros/Cons)

Bettas and mollies are both popular choices for beginner aquarium enthusiasts. However, many people wonder if these two species can coexist peacefully in the same tank. This article will explore the compatibility of mollies and bettas, as well as provide tips and pros/cons for keeping them together.

Bettas, also known as Siamese fighting fish, are beautiful and vibrant creatures known for their long-flowing fins and captivating colors. They are solitary fish and can be territorial, especially towards other male bettas. On the other hand, mollies are peaceful and friendly freshwater fish that thrive in a community setting.

While bettas and mollies can live in the same tank, there are specific considerations to take into account. Understanding the behavior and habitat requirements of each species is crucial for creating a harmonious environment.

This article will discuss the compatibility of these different types of mollies and bettas, provide tips for successfully keeping mollies with bettas, and discuss the potential pros and cons of housing them in the same tank. 

Do Bettas and Mollies Make Good Tankmates?

Will Betta Fish Kill Mollies

Generally, no, Bettas and Mollies are not considered good tankmates. There are several factors to consider:

Betta Temperament: Male Bettas, known for their territoriality and aggression, can perceive the colorful fins and active swimming of Mollies as a threat. This can lead to fin-nipping, chasing, and even more severe attacks. While female Bettas are less aggressive, they can still exhibit territorial behavior, especially towards other females.

Tank Size and Environment: While a larger tank with plenty of hiding spaces can help mitigate aggression, it’s not a foolproof solution. Bettas prefer calm, slow-moving water, while Mollies enjoy swimming in open spaces. Creating a tank environment that caters to both species can be challenging.

Mollie Breed & Gender: Some Molly breeds, like Black Mollies, can be pretty nippy themselves, causing stress and fin damage to Bettas. Additionally, breeding Mollies can quickly overpopulate a tank, creating even more competition for resources and territory.

However, there are a few potential caveats of keeping betta and molly in same tank :

  • Individual Personalities: Some Bettas, especially with experience in community tanks, might tolerate Mollies more passively. However, this is highly dependent on their temperament and shouldn’t be considered a rule.
  • Female Bettas with Mollies: In a considerable tank with ample hiding spaces and well-established territories, some aquarists have had success keeping female Bettas with Mollies. Again, this requires significant experience and careful monitoring.

Alternatives to Consider:

Instead of combining Bettas and Mollies, here are some alternative fish that make good tank mates for your Bettas:

  • Neon tetras
  • Harlequin rasboras
  • Cory catfish
  • Kuhli loaches
  • Shrimp

Always prioritize the well-being of your fish. If you’re unsure about keeping Bettas and Mollies together, it’s best to err on the side of caution and choose incompatible species. Remember, research extensively and talk to experienced aquarists before making any decisions.

Pros & Cons of Keeping Betta and molly in the same tank

Before deciding whether to keep bettas and mollies together, it’s essential to weigh the pros and cons carefully. Both species have different needs and temperaments, and placing them together can lead to problems.


  • Aesthetics: Mollies come in a variety of vibrant colors and patterns, which can complement the beauty of bettas. Having both species in a tank can create a visually appealing underwater scene.
  • Community tank potential: In some cases, with careful planning and a large enough tank, bettas and mollies can coexist peacefully. This can be an efficient way to utilize tank space and create a more dynamic environment.
  • Algae control: Mollies are herbivores and enjoy nibbling on algae. Their presence can help control algae growth in a tank with bettas, reducing the need for manual cleaning.


  • Aggression: Bettas are known for their territorial behavior, especially towards males of other species. Mollies, while generally peaceful, can sometimes be nippy. This can lead to finnipping, chasing, and even physical harm to one or both species.
  • Water parameters: Bettas prefer slightly acidic water with a temperature range of 78°F to 82°F, while mollies prefer slightly alkaline water with a temperature range of 75°F to 80°F. Balancing these preferences can be tricky and may not be suitable for all species.
  • Breeding differences: Mollies are prolific breeders, while bettas require specific conditions for breeding. Their breeding behaviors can clash, causing stress and potentially impacting the health of both species.

Additional factors to consider:

  • Tank size: A minimum of 20 gallons is recommended for attempting to house bettas and mollies together. Larger tanks provide more space for both species to establish their territories and reduce the risk of aggression.
  • Tankmates: Avoid keeping other aggressive fish with bettas and mollies, as this can further increase the risk of conflict.
  • Plants and hiding places: Providing ample hiding places and live plants can help both species feel more secure and reduce stress.
  • Monitoring: Closely monitor your tank for any signs of aggression or stress. If you notice any issues, it’s best to separate the fish immediately.

Overall, keeping bettas and mollies together is not recommended for beginners. It requires careful planning, a large tank, and close monitoring to be successful. If you’re set on having both species, consider researching and implementing advanced tank setups to maximize their chances of peaceful coexistence.

Are Male Betta and Molly tank mates?

Male Betta fish and Molly fish can be kept together in the same tank, but there are specific considerations to keep in mind.

Male Bettas are territorial and can be aggressive towards other fish, especially those with long fins or bright colors, which could trigger their instinct to fight.

However, Molly fish are known to be peaceful and can, therefore, cohabitate with Betta fish if the tank is large enough and has plenty of hiding spots and plants to break the line of sight.

Additionally, it is recommended to introduce the Betta and Molly at the same time to avoid the Betta claiming the tank as its territory before the Molly is added. With proper tank conditions and adequate space, Male Betta and Molly fish can make good tank mates, enhancing the visual appeal and dynamic of the tank while minimizing potential conflicts.

As with any tank mates, it is essential to monitor their behavior and make adjustments as necessary to ensure a harmonious coexistence. 

What kind of fish can Betta live with?

Bettas, despite their reputation for aggression, can actually live longer with some tank mates! However, it’s essential to choose carefully, as the wrong tank mate could end up with a fin-nipped or, worse, Betta. Here are some excellent options to consider:

Peaceful fish:

  • Shrimp: Ghost shrimp, cherry shrimp, and amano shrimp are all good choices. They’re small, quick, and stay near the bottom of the tank, out of the Betta’s way.
  • Snails: Mystery snails and nerite snails are excellent algae eaters and scavengers. They’re too slow to be exciting prey for most bettas.
  • Catfish: Corydoras catfish are peaceful bottom feeders that come in a variety of colors. They’re too small to be a threat to your Betta and will help keep the tank clean.
  • Tetras: Neon tetras, ember tetras, and harlequin rasboras are all peaceful schooling fish that can add a splash of color to your tank. Just make sure the tank is large enough for both the Tetras and the Betta to have their territories.

Fish to avoid:

  • Other male bettas: Bettas are territorial and will fight to the death if housed together.
  • Fish with long fins: Bettas may see long fins as an invitation to attack.
  • Aggressive fish: Fish like cichlids and gouramis can bully your Betta.
  • Large fish: Fish that are much bigger than your Betta may see it as prey.

With careful planning, you can create a thriving community tank with your Betta as the star. Just remember to do your research and choose tank mates that are compatible with your Betta’s temperament and needs.

What fish live best with mollies?

Mollies are peaceful and social fish that can thrive in a community tank with a variety of other species. They are best kept with other peaceful and similar-sized fish that can tolerate the same water conditions. Good tank mates for mollies include other livebearers such as guppies, platies, and swordtails.

These fish all prefer similar water parameters and have a peaceful demeanor, making them compatible companions for mollies. Additionally, mollies can also be kept with peaceful freshwater species such as tetras, danios, and Corydoras catfish.

It’s important to avoid aggressive or fin-nipping species, as well as fish that require vastly different water conditions. Providing mollies with suitable tank mates will ensure a harmonious and thriving community tank, allowing the mollies to display their natural behavior and interactions with other fish.

Overall, choosing peaceful and compatible tank mates will help create a healthy and balanced aquatic environment for mollies.

Can I put Molly fish with Betta?

While possible, mixing Mollies and Bettas is risky. Bettas can be aggressive, especially towards Molly males’ vibrant fins. Consider a larger tank with plenty of hiding spaces and peaceful tank mates like neon tetras instead.

Are mollies prolific breeders?

Yes, mollies are prolific livebearers! Expect frequent batches of fry (baby fish) as females can give birth every 4-6 weeks, with each litter numbering 20-40 fry. Separate sexes or prepare for a molly explosion!

How many mollies should be kept together?

Start with at least five female and male mollies, including 2-3 females per male. This avoids male harassment and spreads the bioload. Adjust for tank size and consider adding more females for larger groups.

What fish pair well with mollies?

Mollies generally pair well with peaceful fish like guppies, platies, and swordtails. Avoid aggressive species. Compatible tank mates include tetras, danios, and Corydoras catfish.

Do mollies need companions?

While not strictly required, mollies thrive in groups! These social fish enjoy the company of their kind, reducing stress and displaying natural behaviors like shoaling. Aim for at least 3 mollies, ideally with more females than males, to balance the group.

Can Plecos and Mollies live together?

Yes, Plecos and mollies can coexist in the same aquarium, provided the tank is spacious and well-maintained. Ensure proper water conditions, avoid overstocking, and monitor for any aggressive behavior.

Can Betta fish and mollies live together?

Betta fish and mollies may not be ideal tank mates. Male bettas can be territorial and aggressive, posing a risk to mollies. If attempting to keep them together, monitor closely for signs of aggression and provide hiding spots for mollies.

What fish Cannot be with a betta?

Avoid housing bettas with aggressive or fin-nipping species like other bettas, Gouramis, and some tetras. Also, steer clear of long-finned or brightly colored fish that might trigger a betta’s aggression.

Can Female Betta Fish Live With Mollies?

While possible, female Bettas and mollies can be a tricky mix. Bettas, even females, can be territorial, especially towards vibrant fins like those of male mollies. Consider peaceful tank mates like female guppies or platys for a safer, more harmonious community. Remember, research fish compatibility before adding new fin friends to the betta tank!

Why You Should Avoid Balloon Mollies?

Skip the balloon mollies! Their cute, rounded bodies are unethically bred, causing health problems like swim bladder issues and organ dysfunction. Choose healthier alternatives like regular mollies or other livebearer species for a happier, more ethical aquarium.

Can I keep Betta with Dalmatian Mollies?

Tread carefully with Bettas and Dalmatian Mollies. While Dalmatians are less flashy than standard Mollies, their fins can still trigger Betta aggression. Consider a larger tank with plenty of hiding spaces and peaceful tank mates like neon tetras to reduce stress and fin-nipping.

How do you identify male and female mollies?

Distinguishing male and female mollies is relatively easy. Males have a gonopodium, a modified anal fin resembling a narrow tube, while females have a larger, fan-shaped anal fin. Additionally, females may exhibit a gravid spot when pregnant, a dark spot near the anal fin.

Can I put 2 female bettas with one male Betta?

No, it’s not advisable to house two female bettas with one male Betta. Female bettas can be territorial and may exhibit aggression towards each other, leading to stress and potential harm.

Can I have a betta and Mollies living in a 20-gallon tank?

Proceed with caution! Mollies’ fins and Bettas’ territorial nature can clash. A heavily planted 20 gallon with peaceful tank mates like tetras is safer for your Betta. Observe and be ready to separate if needed.

Can Betta fish and black Molly live together?

Risky mix! Bettas can be aggressive towards Mollies’ vibrant fins. Opt for peaceful tank mates like neon tetras for a more harmonious 20-gallon community.

Do mollies like aquarium salt?

Yes, mollies generally benefit from aquarium salt, as it mimics their brackish water natural habitat. Adding a small amount can enhance their overall well-being and aid in preventing specific health issues.


In conclusion, mollies and bettas are fascinating fish that can bring vibrant colors and lively personalities to any aquarium. Whether you’re a beginner or an experienced fish enthusiast, these unique species offer a range of options for creating a thriving aquatic ecosystem. From their stunning appearances to their intriguing behavior, Betta and Molly fish never fail to captivate and entertain. So, if you’re looking to add a touch of beauty and charm to your underwater world, don’t hesitate to consider bettas and mollies as your next aquatic companions.

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About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

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