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Can Betta And Mollies Live Together?

If you want to know a concise answer to the question, sorry to disappoint you, but there’s none.

Some say that Betta and Mollies can stay together in harmony while others disagree!

What are their individual reasons and evidence? Let’s discuss it!

It’s genuinely every fish owner’s dream to create a community in their aquarium. However, you can’t just put any species together.

Many things come into consideration when you plan to put two different types of fish together in a tank, and not all species are as easy as you might think.

Mollies and Betta are a classic example of why it’s necessary to do your research before putting the two fishes together in a single container.

The combination is risky; hence it may or may not work depending on several different factors.

In the following guide, we’ll discuss everything, starting from the basics.

We’ll start from the essential introduction to the two species to their compatibility score and discuss why they should or should not be together in a tank.

Before you think about putting these two types of fish together, you must know about Betta and mollies as individual fish.

Learning what their species is like and where they come from will help you understand the comparison we will do later.

Betta Fish Introduction

Video: “Betta Fish Care Guide: Everything You Need to Know!”

Betta fish has another more common name, Siamese fighting fish. They have beautiful but short grey-green fins.

However, you will find several varieties in the market now since selective breeding is quite common. You’ll find various gorgeous color combinations and lengths and types of fish.

This particular species is Asian oriented, and you will usually find them living in slow-moving and shallow waters in streams and marshes and sometimes ponds.

The male Betta fish create bubble nests for their babies and protect them from predators.

These fish are also diurnal like humans, meaning that they stay more active throughout the day and tend to rest during the night.

The most crucial factor to remember here is that they require darkness to rest and sleep.

An interesting fact about betta fish is that they always recognize their owner and guardian.

If they see their care-taker approaching them, you will notice them swimming excitedly.

They’re a very curious species, and every time you put anything in the tank, you’ll see immediate excitement and enthusiasm among them.

Can Betta Live Alone?

Betta fish like to mark their territory. In fact, they hate it when another fish invades their personal space. They get violent and aggressive.

Thus, it is clear that Betta fish can do just fine on their own and actually prefer being that way.

Can Betta Live With Other Fish?

Not really!

Betta fish prefer to live alone, and it can get quite dangerous if you put other fish in the same tank.

However, the primary reason why they get so violent is that they feel like they don’t have enough space to swim around in.

So, if you combat that issue, you might not have to deal with an aggressive beta first in the first place.

Maybe, just maybe, you might even be able to introduce another fish in the tank successfully.

So, keep larger aquariums your primary priority if you are thinking about doing this merge.

Molly Fish Introduction

Video: “Molly Fish Care and Breeding: Let’s Clear up All The Confusion!”

Mollies have several other common names, Common Molly and short-finned Molly, being some of them.

These beautiful fish are incredibly adorable as babies. They have big, black eyes that are the highlight of their entire appearance.

They have a flat body with taller centers. Their shape becomes narrow as it moves towards the mouth. The caudal fins are relatively larger and shaped like a fan.

These friends are sometimes colorful and transparent in other species.

This beautiful fish likes to live in freshwater streams, coastal brackish waters, and the Mexican marine waters.

Other popular regions of origin of this exotic fish include Central America and the Southern United States.

The critical thing to remember about Mollies is that they are very prone to developing a condition called shimmies. Don’t worry; it’s not anything infectious or contagious.

It’s just a group of stress-related symptoms that develop in cases of extreme environmental stress.

Can Mollies Live Alone?

Mollies can do just fine on their own. They can live in a 10-gallon tank by itself without any trouble whatsoever.

However, since this is not their primary preference for lifestyle, they tend to get isolated and depressed if they are alone for an extended period.

If you don’t want to risk introducing other species in the tank, at least make sure that you keep a couple of mollies together, so they’re not lonely.

If you wish to put your Mollies in a community, they prefer being around other live-bearing species.

Not that it’s a compulsion, but if you’re making a list of preferences and requirements for Molly’s new roommate, keep this one in mind!

Can Mollies Live With Other Fish?

Mollies are very social fish.

They love to be around other fish, and you can introduce other friendly aquatic species in the same tank as a Molly without any worry in the world!

Can Betta And Mollies Live Together In The Same Tank?

Betta and mollies are a complex aqua-life combination, and not a lot of people take the risk of merging the two in their home aquariums.

The best way you can determine whether or not you can keep them together is to understand how they are similar or different, and the ratio of these aspects.

The Similarities Between Betta and Mollies

The following are some of the most significant similarities between the two fish species.

These similarities are also important reasons why you can successfully keep them together in a single tank.


Water Requirements

It is common knowledge that Mollies live longer in slightly brackish water.

Even though many people think that such an environment is not suitable for Betta fish, the International Congress of Betta states otherwise.

In fact, the jury concludes that aquarium salt might even be beneficial for the fish and prevent growth problems.

Plus, both Betta and mollies have a similar liking for neutral pH level, which is 7.0.

Similarly, Mollies have an optimal temperature range of around 70 to 80 degrees Fahrenheit and so does Betta.

Hence, the water environment and maintenance are not much of a problem with these two species.



In terms of diet and food, both of these aquatic species have the same preferences. Molly fish is an omnivorous species. It feeds on plants, algae, and invertebrates.

In-home aquariums, you should feed them flake food but make sure they’re high-quality. You can also provide them different vegetables, and they’ll do just fine.

Betta fish are carnivores. They prefer and require high-protein animal food in the wild, paper for larvae, and adult insects.

However, at home, you can feed them fish meal flakes and pellets. Freeze-dried and frozen bloodworms also do well.

Thus, it is easy to find some sort of food that goes well for both species. This way, you don’t have to make a double effort.



While most people miss out on this crucial aspect, it is essential to consider the fish’s size when you decide to put them together.

In this case, fortunately, both Betta and mollies have a similar average size.

Betta fish usually grow as long as 2.25 inches when they’re fully matured. If given the ideal conditions and care, they might even reach 3 inches.

Mollies have relatively larger mouths and eyes. The male fish can grow as long as three inches while the female can grow approximately 4 inches.

Keep in mind that these sizes are average numbers when the fishes are about six months old.

As the Molly fish enters its second year of life, its fins start to grow even larger. If you want a reference, a 20-gallon tank is a perfect size, to begin with.

The Differences Between Betta and Mollies

Despite the similarities between a molly and a betta, there are also some significant differences between the two species.

As mentioned before, you must learn why you can and cannot keep mollies and Betta together.

This way, you can make an appropriate decision for yourself based on your perspectives on lifestyle.



In general, the difference in sizes is not too significant to be a problem.

However, considering that mollies continue to grow after six months of age, they might develop more massive than an adult beta.

It means that, after a particular amount of time, one of the fish species will grow significantly larger than the other.

It is essential to keep this fact in mind when you are buying an aquarium or any container.

If you know you’re going to change the tank eventually, there’s no need to worry about the future size differences.

However, if you plan to make a one-time investment, ensure that you buy a tank big enough for both fishes to move around regardless of how big they get.



Even though their expected life span is about five years, most Molly fishes tend to die after one or two years of age.

In contrast, the betta fish have a longer lifespan of about four to five years on average.

While this difference is not much of a problem in terms of their compatibility, it is still something you should keep in mind.

Since many people like to replace their fish, it might be a point of concern to them that they will have to replace their Mollies after a few years.

If that’s the case, don’t worry. Mollies are live-bearing, which means that they give birth to fry instead of eggs.

So, by the time your primary mollies die, you’ll have plenty of others in the tank.



Last but definitely not least, understand and acknowledge that Betta fish are relatively more aggressive, and they are famous for their violent behavior.

The reason behind their anger-management issues is that they are very territorial, and they like to mark their space.

If their room is too small or other fish are trying to invade it, they’ll snap!

The males are generally more prone to aggressiveness, and they tend to attack each other if you put them together in a confined space.

In contrast, Mollies are a relatively more peaceful bunch. They are friendly, and they like to stay active.

This enthusiastic species is also very social, and it is not common for them to be violent around other fish types. However, it’s not abnormal, either.

When Molly encounters a competitive and aggressive opponent or notices danger around them, they can retaliate.

Thus, you must keep the tank big enough for both of the species to live in harmony.

Their Compatibility Score

In terms of ranking and scores, Betta’s compatibility with a Molly is somewhere around 6 or 7/10.

As mentioned earlier, there are several reasons you should or should not keep the two together.

Hence, the final decision entirely depends on how you manage to keep them together in a tank and what kind of fish you’re getting.


So, in conclusion, Betta and mollies are reasonably compatible, and you can keep them together as long as you know what you’re getting yourself into.

The biggest mistake that fish-owners make when they’re trying to merge different communities in a tank is that they don’t know about any of them individually.

Learning about the care requirements, preferences, lifestyle, and lifespan of the different species is essential to determine whether they can stay together in harmony.

All of this information and research are especially important if one of the two species is an aggressive one; in this case, it is the betta fish.

In order to ensure that one of the fish types will not hurt the other one, you must do your homework.

If you are sure that you can prevent all such circumstances, it’s entirely safe to combine Mollies and Betta in a single tank.

Aaron Boyd
Aaron Boyd

Hello, I’m Aaron Boyd, the proud owner and author behind Aqua Movement. I hope my article was able to answer your questions. If you want to learn more about me, click the home icon above.

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