Can Betta Fish Live With Mollies? Everything You Need To Know

    Can betta fish live with mollies

    Mollies are fish that many people like to keep in their tanks. But can Betta fish live with Mollies? That’s the question on a lot of people’s minds.

    The answer is yes and no. It depends on a few factors, such as your tank’s size, your fish’s temperament, and whether or not you’re willing to put in the effort to make it work.

    In this blog post, we’ll explore whether or not these two types of fish can coexist peacefully. We’ll also look at tips for keeping Bettas and Mollies together if you decide to go ahead and try it. So, read on to learn more!

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    Can Betta Fish Live With Mollies? Factors To Consider

    There are many things that you need to consider before even thinking about keeping Betta fish and Mollies together.

    Tank Size

    The first thing you need to consider is the size of your tank. If it’s too small, then it’s not possible for Bettas and Mollies to live together peacefully.

    Think about it. One Betta fish already needs a minimum of 5-10 gallons. Mollies also need a lot of space to swim around and produce a lot of waste. Due to this, they typically require a tank that’s at least 20 gallons.

    So, if you don’t have a huge tank, it’s best to stick to one type of fish. In fact, if your tank is on the small side, it’s best to just stick with Bettas. Mollies can get stressed if they don’t get much swimming space, which might not turn out well for your fish.

    Temperament Of The Fish

    The next thing you need to consider is the temperament of your fish. Betta fish are known for being aggressive and often attack other fish they see as a threat. Mollies, on the other hand, are relatively peaceful fish. This means that if you put them together in the same tank, there’s a good chance that the Betta will try to attack the Molly.

    Now, this doesn’t mean that Bettas and Mollies can’t live together. Some Bettas are perfectly content living with other fish. But, it’s something that you need to be aware of before putting them together.

    If you’re not sure whether your Betta will be okay with other fish, then it’s best just to keep him alone. It’s better to be safe than sorry.

    Tank Setup

    Another thing you need to consider is whether or not there are enough hiding places in your tank. Betta fish like to have a lot of places to hide, and they also want to have a lot of places to swim. If your tank isn’t set up correctly, then the Betta will feel stressed out and could become aggressive. The same is true for Mollies.

    When setting up your tank, ensure plenty of plants and other decorations for the fish to hide behind. You should also ensure that there is plenty of open space for the fish to swim around. If you do this, then it will be more likely that the Betta and Molly can coexist peacefully.

    Water Conditions

    Another vital factor to consider is the water conditions in your tank. Both Bettas and Mollies need warm, well-oxygenated water. The water should also be clean and free of toxins.

    If the water conditions in your tank are not ideal, it will be tough for the fish to survive. This is especially true for Bettas, as they are very sensitive to changes in water conditions. For this reason, it’s important to ensure that the water in your tank is always clean and well-maintained. You can use Seachem Prime to ensure the water is perfect before adding the fish.


    The last thing you must consider is how you will feed your fish. Both Bettas and Mollies are carnivores, meaning they need a diet mostly of meat.

    You can either feed them live food, such as worms or brine shrimp, or you can give them freeze-dried food. If you’re going to provide them with freeze-dried food, make sure it’s high in protein and designed specifically for carnivores.

    You should also make sure that you’re feeding your fish enough food. If they’re not getting enough to eat, they could start fighting each other.

    Betta Fish Basics

    Scientific Name: Betta splendens
    Care level: Easy
    Temperament: Aggressive
    Lifespan: 3 years
    Size: 2 ½ – 3 inches (body)
    Diet: Carnivorous
    Family: Osphronemidae
    Minimum Tank Size: 5 gallons


    Bettas, also known as Siamese fighting fish, are relatively carefree fish that require little maintenance. However, they do have their own unique needs when it comes to care. We’ll go through the fundamentals of Betta fishkeeping in this part.

    Care Level

    Betta fish are simple to care for, so many fish keepers consider them beginner fish. If you want to start caring for a Betta of your own, you just need an appropriately-sized tank, a heater, and some plants.


    The average Betta has a lifespan of around three years. Some can live up to 5 years, while others can live more than that.


    Bettas are known for being aggressive and often attack or flare at other fish they see as a threat, whether it’s female Bettas or male Bettas.

    However, some Bettas are perfectly content living with other fish. It’s important to remember that each Betta is different, and you’ll need to observe their behavior before putting them together with other fish.


    Bettas are carnivores, meaning their diet should consist mostly of meat. You can either feed them live food or give them freeze-dried food. If you’re going to feed them freeze-dried food, make sure that it’s high in protein and designed specifically for carnivores.

    When hungry, Bettas can eat anything that fits inside their mouths – even baby fry or human food.


    In the wild, Bettas can be found in Southeast Asian countries like Thailand, Laos, Cambodia, and Vietnam. They live in stagnant waters that are often murky and filled with plants and vegetation. They don’t mind jumping from these bodies of water to find a more suitable home.

    Bettas are freshwater fish, but they’re hardy enough to tolerate brackish waters for short periods.

    Scientific Family

    Bettas, also known as Siamese fighting fish, belong to the Osphronemidae family, which contains other popular freshwater fish like Gouramis and Paradise.

    Tank Setup

    Bettas are a perfect beginner fish because they’re very low-maintenance and forgiving when it comes to water conditions. They’ll be happy if you keep the water clean and provide them with a warm place to hide.

    Additionally, the ideal water temperature for Bettas ranges from 76 to 82 degrees Fahrenheit. A heater is necessary if you don’t live in a tropical country.

    Minimum Tank Size

    Bettas are quite solitary animals, so you don’t have to worry about keeping them in a bigger tank. However, they still have space requirements for a healthier and stress-free life – bowls and small basins simply wouldn’t do, as they won’t have the space to explore and will be constantly stressed out.

    We recommend a minimum of 5-10 gallons for your Betta fish tank. The bare minimum is around 3 gallons, but ideally, it should only be for young or small Bettas.

    Molly Fish Basics

    Molly fish, Poecilia latipinna

    Scientific Name: Poecilia sphenops
    Care level: Easy
    Temperament: Peaceful
    Lifespan: 5 years
    Size: 4-4.5 inches
    Diet: Omnivorous
    Family: Poeciliidae
    Minimum Tank Size: 10 gallons

    Now that we know the basics of caring for Bettas, let’s discuss the basics of keeping Molly fish.

    Care Level

    Mollies are easy to care for and considered beginner fish, just like Bettas. Many aquarists start by taking care of Mollies and other smaller schooling fish in a community tank. That’s because all you need to take care of this small fish species is a tank, a heater, and some plants.


    The average Molly has a lifespan of around 3-5 years. Some can live longer than this, while others might not even make it to 3 years. It depends on the level of care that they get in your tank. Although they’re pretty hardy, you need to ensure that their minimum needs are met so they can have a full and happy life.


    Mollies are peaceful fish that get along well with other fish, making them good tank mates. They’re not known for being aggressive, but they can be if they feel threatened. However, most Mollies are perfectly content living with other non-aggressive fish.


    Mollies are omnivores like Bettas, which means they eat plants and animals. They’ll eat anything they can find in the wild, including algae, small insects, and even fry.

    In captivity, you can feed them various food, such as flakes, pellets, live food, and frozen food. Just make sure that their diet is well-rounded and that they get all the nutrients they need.


    Mollies are found in the wild in brackish and freshwater habitats. They can live in salt and freshwater but prefer freshwater rivers in tropical areas.

    There are some instances of Mollies being able to swim into the sea, albeit for short periods. This points to their hardy and adaptable, making them even better choices for beginner aquarists.

    Scientific Family

    Mollies are a part of the Poeciliidae family, which contains other popular freshwater fish like Guppies and Platies.

    Tank Setup

    Setting up a Molly tank isn’t difficult. They don’t have high demands, and they’re pretty adaptable. However, there are a few things that you need to take into consideration.

    For instance, Mollies prefer tropical waters between 72 and 78 degrees Fahrenheit. Similar to Bettas, you should add a heater to your tank if you live in a colder climate.

    You also need to make sure that the tank is well-aerated. Mollies are sensitive to poor water quality, so a good filter is necessary. You can start by using Tetra Whisper Easy to Use Air Pump and attaching a sponge filter to it.

    Minimum Tank Size

    The minimum tank size for Mollies is around 10 gallons for a group of four. However, we recommend a 20-gallon or larger tank if you plan to keep more than this number. While small, they can be quite active and need this space to swim around and play.

    Best Species of Mollies That Can Live With Betta Fish

    Molly fish tank mates

    The best species of Mollies to keep with Betta fish are:

    Black Molly

    Black Mollies, as their name suggests, are entirely black. They have a reputation for being one of the hardiest species of Molly, and they’re known to be very adaptable.

    Black Mollies like eating algae, so they’re a good choice for aquariums with live plants. They can grow to be around 4 inches long and have a lifespan of around five years.

    Like most other Molly variations, they breed rather fast. However, don’t expect their fry to reach adulthood, as Bettas enjoy going after and eating any fry they can fit in their mouths. If you don’t want this to happen, it’s better to either not keep Black Mollies with Bettas or to remove the fry as soon as they’re born. You can also keep all females or all males.

    Dalmatian Molly

    Dalmatian Mollies are one of the most popular types of Molly.

    They’re easily recognizable by their black and white spots, which are similar to those of a Dalmatian dog. Some have more black, while others have more white or even silver.

    Dalmatian Mollies can grow to be around 4 inches long and have a lifespan of 4 to 5 years. They’re known to be very peaceful and make great tank mates for other peaceful fish, such as Bettas.

    They’re fast swimmers and can avoid the much-slower Bettas when necessary – just make sure to give them lots of space to swim around in and cover for hiding when needed.

    Lyretail Molly

    This type of Molly is a popular choice for adding Bettas. Not only are they hardy and entertaining to watch, but Lyretail Mollies also echo the kind of gracefulness that we’ve come to love of Bettas because of their long, lyre-like tail shape where they get their name from.

    Lyretail Mollies are generally peaceful, engaging, and beautiful. Their coloration ranges are the same as a typical Molly, which means you can expect a lyretail version of every Molly color you can think of.

    Females grow up to 5 inches and males up to 3, with males sometimes displaying harassing and territorial tendencies. They can live for up to 5 years, which makes them ideal for Betta companions.

    While Lyretail Mollies would look good with your Bettas, you need to have additional precautions when adding this fish because the Bettas may mistake their long fins for competition and become aggressive. Ensure that there’s plenty of swimming space for their adult sizes and plenty of hiding spaces for both Mollies and Bettas.

    Gold Dust Mollies

    Gold Dust Mollies are another variety that can be nicely added to a Betta fish tank and make for a peaceful and visually-appealing companion to your siamese fighting fish.

    These vibrantly-colored varieties get their name from the gradient of their scales ranging from golden orange to shiny black. These fish have unique colorations, but one common factor is that the area where the two colors meet and clash will have irregular and interesting combinations – hence where the “gold dust” term comes from.

    This variety can add an interesting visual appeal to the tank with the right Betta coloration. More than that, they’re active swimmers around the tank and are also one of the most peaceful varieties of Mollies. This makes them ideal for Betta tanks.

    Precautions To Take Before Adding A Betta To A Molly Tank or Vice Versa

    Can betta fish live with molly fish

    While Mollies are, in general, peaceful community fish, they also have special considerations you need to consider before you add some to your Betta tank.

    Before you walk to the pet shop or make your next order online, read these factors and ensure that you know that you’re prepared.

    Aquarium Size And Cover

    Mollies can grow to be pretty large fishes, especially females. While you might purchase cute juvenile fishes in the pet shop, they can quickly grow to about five inches if conditions are right.

    If you plan to add Mollies to your tank, you must ensure that you have the space to house the number you’re planning to add.

    Consider their size when they become full-blown adults, and add to that the size of the full-grown Betta that you also want to keep, and you will arrive at a significant aquarium volume. You don’t want them to quickly overcrowd your aquarium – especially since Bettas are largely solitary and will be stressed if they feel crowded.

    Breeding Tendencies

    Mollies are livebearers – and livebearers are very fast breeders. They can multiply fast, and while this is generally a good thing, you need to prepare for such as population explosion so that you won’t collapse your aquarium ecosystem.

    On the flip side, Bettas will enjoy having a high-protein snack like bloodworms and brine shrimp in the tank. Even if you don’t intend for Mollies to breed, it can present an additional food source for your Betta while simultaneously controlling their population.

    If you’re breeding Mollies, specifically, you shouldn’t be adding them to a Betta tank.

    Bettas are voracious carnivores, and they are excellent hunters. Your Molly fry will face an additional danger if you keep them in a Betta tank, as they will have more predators to hide from – including their own parents.

    Feeding Tendencies

    Mollies are voracious feeders and very fast swimmers.

    Aquarists often forget that your Betta might not be able to keep up with Mollies when it comes to feeding. If your Bettas are particularly slow, Mollies tend to eat all of the fish food before your Betta can have enough.

    You can prepare for this by giving a variety of fish food that populate different parts of the tank. For example, you can feed floating flakes for Mollies to feast on the surface of the water, while your Betta might appreciate fish food that sinks to the middle regions.

    What To Do If Betta Fish And Mollies Don’t Get Along

    What To Do If Betta Fish And Molly fish Don’t Get Along

    You might already have taken all the precautions before adding Mollies and Bettas together in one tank, but you simply can’t predict every fish’s temperament.

    This means that there’s a chance that your Betta and Mollies might simply not like each other, and you’re going to have to take extra steps. Look through the following options to deal with this situation.

    • Transfer both fish to a bigger tank. If you want to keep the setup going, you can mitigate the potential conflicts between them by putting lots of extra space and plant and hard cover between your Bettas and Mollies.
    • Transfer some fish to another aquarium. If you can’t transfer both to another tank, you must pick one species to move to another aquarium. Bettas will do better alone, while Mollies will live well with other non-aggressive fish or communities.
    • Donate or sell one species. You might not have another tank to spare, so you’re going to have to donate one of the fish species you have. You can give them to friends or family or go to local enthusiast groups.

    Regardless of your measures, you must ensure that you’re entirely removing one species from the original aquarium that your Betta and Molly share.

    Is It Worth Keeping Betta Fish And Mollies Together?

    Betta fish and Mollies make an excellent aquarium pair, and it will be worth seeing both species in one tank if done well.

    However, whether it’s worth it is ultimately up to you. There will be instances when you might have to conclude that it’s not worth it because their aesthetic appeal might not be what you expected, or you might have the wrong size of aquarium, or they’re not getting along as they should.

    In these cases, it’s essential to understand when to quit and always to have a backup plan. You need to know what factors to consider when mixing the two species and what to do in case your Betta and Mollies don’t get along.

    Fortunately, the previous sections already went to that in detail for you, so now you’re well-equipped to deal with whatever happens in your experiment.


    Bettas and Mollies are among the most popular aquarium pairs because of their aesthetic appeal together and because their temperaments and mannerisms theoretically can fit well with each other.

    However, there are still plenty of factors that you need to consider before taking the leap – and you also need to know what to do in case things don’t work out. Fortunately, we have already covered all of those in this article.

    Remember what you read as you go about this experience, and make sure to enjoy the process!

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