Can Bettas And Mollies Live Together?

Last Updated on 2024-05-25

Finding tank mates for your betta isn’t the easiest task. If the tank mates are too colorful or have long flowing fins, then they’ll probably end up getting attacked. And on the other end of the spectrum, some fish will stress your betta out. So you have to find the fine line between the two. One breed of fish that falls into this category are mollies. Keep reading to find out how bettas and mollies can live together.

A Guide To Bettas And Mollies

Before you even think about whether it’s a good idea to add bettas and mollies together it’s important to make sure the water parameters they both need are similar.

pH Level

A betta needs a pH level of 7.0 to thrive, whereas a mollies pH level can vary between 7.0-7.8. As you can see while a bettas pH needs are at the very low end of that spectrum, they’re still there. So different pH levels aren’t going to be an issue.


The next most important consideration is temperature. If the temperature in your fish tank isn’t right it could result in your betta and mollies having a weakened immune system.

It’s often said that the ideal temperature for bettas is 78°F. However, anything in between 76-80°F is going to be suitable. And mollies are a lot more flexible when it comes to the temperature they can survive in. Water between 68-82°F is going to be absolutely fine for mollies. And as you can see a bettas ideal temperature falls nicely within this range.

Salt Water

Here is where things become a little more complicated. It’s often said mollies survive better in water that is slightly brackish. On the other hand it’s a common belief that bettas need solely fresh water.

But a lot of betta owners have recently started using aquarium salt in their tanks as a tonic or preventative against illness. It’s believed that a small dose of aquarium salt can actually increase a bettas immune system as well as their slime coat. The IBC (International Betta Congress) even support the use of aquarium salt.

But if you still don’t feel comfortable adding aquarium salt to your tank then you should ask the pet store what water they breed their mollies in. If they’re bred and raised in fresh water then they’ll survive just fine in fresh water.

How Big Do Mollies Get?

If you plan on having mollies in your tank you should remember that they can grow up to an inch bigger than your betta. Because of this, you should consider what tank you plan on using. You may hear people recommend a minimum of 10 gallons to house mollies, but in all honesty 20 is going to be a lot better.

Not only is a 20 gallon tank going to support your mollies bioload and waste better, but it’s also going to give them enough room to swim.

And it’s important to remember that mollies are social fish. They need to live with other mollies or they will become stressed. So a 20 gallon tank is the best option to give your betta and mollies plenty of room.

If you don’t have a 20 gallon tank but you’re interested in buying them here are some of the best 20 gallon tanks on the market.

Lifespan Of Mollies

If you plan on having mollies in your tank then you should know in some circumstances they can live up to 5 years. However, it’s more than likely they will only live for 2 years in your tank. But that doesn’t mean you’ll have to buy mollies to replace them. Mollies are livebearing fish which means they don’t lay eggs but give birth to fry. So your tank could potentially always have mollies in it.

Freshwater Balloon Fishy Molly Aquarium Gold
Freshwater Balloon Fishy Molly Aquarium Gold

Mollies And Livebearing

If you have any female mollies in your tank then the chances are they’re going to give birth to a lot of fry. Even if you only place female mollies into a tank they can store sperm. In fact, they can give birth months after they’ve been in contact with other males.

This means you have to be cautious. Too many fish in a tank will eventually cause the water quality to drop, which could result in harm coming to your betta and mollies. So what are the solutions?

Leave The Fry

Luckily, most fry will end up being eaten by other fish in the tank, even their own parents. If you’re worried about fry growing in your tank then the chances of all of them growing to adulthood are slim. However, in every batch, it is possible for at least one fry to make it to adulthood.

To lessen the chances of this happening you should try to remove as many hiding places for them as possible. If you have gravel with large gaps in between consider switching to sand or smaller gravel. (There’s a vast variety of great gravels you can choose from.)

Just leaving the fry will result in the vast majority of them being eaten.

Only Add One Sex To Your Tank

Another option is to only add one sex to your tank. However, unlike platies, I would only recommend adding females. While initially, it may seem like a bad idea, in the long run, it will be better.

Male mollies can be quite aggressive to one another when trying to establish a hierarchy. While they wouldn’t be aggressive towards your betta, he may still get stressed out from all the commotion. If you only have males they’re all going to be fighting for the alpha spot, because there’s nothing else for them to do.

While female mollies pose the risk of birthing in the beginning, after a while they won’t be able to reproduce anymore. At this point, you know that your aquarium is safe from any more baby fish.

Look After The Babies

If you have a nurturing side why not look after the fry? You’ll need a separate tank to put them in but many people find it very rewarding. The only problem comes when you begin trying to get rid of them. You can’t release them in the wild and there’s no other humane method of getting rid of them.

Give Them Away/Sell Them

Just because you don’t want the fry doesn’t mean other people don’t. If you have any friends you can give them some of your mollies, or try to take them to a store to sell them.

Some people will even use fry to feed other animals, so there is a multitude of options you can choose from.

What Is The Temperament Of Mollies

When talking about the temperament of fish it’s important to know that all fish are different. While the vast majority of them will act one way, that doesn’t mean they all will. But with that being said mollies are generally seen to be extremely peaceful fish. Especially in circumstances when one male molly is being kept with two female mollies.

However, if you house all male mollies then as previously mentioned you may notice aggression amongst them. This is because they’ll only be interested in finding out who the alpha male in the group is. But with that being said it’s rare that mollies will ever begin attacking bettas because it’s not in their nature. The only thing you’d need to worry about is the small chance of fin nipping occurring.

Should You Worry About Your Betta?

If you’re worried about aggression in your tank it’s far more likely that your betta is going to be the aggressor. If your betta has a bad temperament then he may not tolerate other fish in his tank. When you add mollies to your tank you should keep an eye on them for the first few days. If you notice any signs of damage on them then it may not be safe for them in your fish tank anymore.

Remember, it’s common for bettas to flare in the first few days and let the other fish know where their territory is, but if it goes on longer then a few days or you notice your betta getting stressed, then you may have to remove the mollies.

If you plan on having bettas with other fish, it’s always a good idea to add the betta last. That way he’ll feel like he’s going into another fishes territory and not the other way around.

Can Female Betta Fish Live With Mollies?

Adding female betta fish with mollies can often be even easier than male bettas. While females are aggressive, they’re not going to be nearly as aggressive as the males. However, if you have a betta sorority, you should make sure that you have a larger tank.

Females often become more aggressive together as they’ll try to find a pecking order. So a larger tank is going to reduce the risk of mollies getting caught up in it.

Knowing the different behavior, tank requirements and diets of multiple fish is a difficult task to accomplish. In fact, there are fish that can live with your betta you haven’t even thought of yet! If you want to know about every fish that can live with your betta then click here.

What Do Mollies Eat?

Bettas and mollies have similar diets as well, which is another great reason to have them as tank mates. While bettas are opportunistic eaters, mollies prefer a more omnivorous diet. So as long as you focus on giving your betta the required meat he needs, he’ll get enough fiber from anything you feed your mollies!

When feeding your mollies you should make sure you’re giving them a good balance of meat and plants. Adding live food into the tank is also going to help keep your betta and mollies healthy. So when you add the food you want to stick to high-quality fish pellets and flakes, frozen meat, and live food such as daphnia, bloodworms, and mosquito larvae!

You’ll also notice that your mollies will occasionally graze on algae as well! Check out 17 other great algae eaters for your betta tank!

What To Do When Feeding

Sometimes your betta could become very hostile when it comes to feeding, or perhaps even your mollies will be. If this is the case there are things you can do to limit the problem.

First of all, you can spread fish food down one end of your tank to attract the mollies, and then drop some pellets or meat on the other side for your betta to eat. Doing this lets you know for sure that your betta is getting enough food and won’t starve. (Remember bettas only need a small amount of food every day, but they will keep eating no matter how full up they are.)

Another thing you can try is catching your betta in a net and dropping food into the net. This way there is no possible chance of your mollies getting the food and you’ll know without a doubt that your betta has had enough food!

If you’re interested in knowing about 30 other tank mates that can live with your betta then check out this HUGE list of betta tank mates!

bettas and mollies

Different Types Of Mollies

There is a whole range of mollies you can add to your tank, but that doesn’t mean you should add all of them. Some great mollies to add to your tank are:

  • Common Mollies 
  • Midnight Mollies
  • White Mollies
  • Golden Mollies
  • Lyretail Mollies
  • Dalmatian Mollies
  • Sailfin Mollies

Every one of these mollies will make a great addition to your tank and will get along well with any other fish in the tank. However, there is one type of molly you should definitely avoid.

Why You Should Avoid Balloon Mollies

If you’re considering getting balloon mollies then you should strongly consider picking something else. As you can guess balloon mollies look like their bellies have ballooned up. While this makes them more interesting, it’s definitely not healthy.

Balloon mollies are selectively bred mollies with scoliosis. Not only is this cruel, but it also has implications for the fish. Because of a number of factors balloon mollies often die quicker, and their bodies will always be uncomfortable.

The misshapen spine makes it hard for them to swim. On top, of this the way their bodies are cause their organs to become more compact, which makes it more dangerous for them to give birth and will cause a lot of discomfort.

Because of this, you should pick other mollies over balloon mollies to live with your betta.

Wondering where you can find a complete guide on Betta fish care? Click here!


So when it comes to adding tank mates with your betta, mollies are a great choice. Some of the main things to remember when adding mollies and bettas together are:

  • Mollies survive better in slightly brackish water, while you may think bettas wouldn’t like this the international betta congress approve of using aquarium salt as a general preventative and believe it’s also beneficial to bettas.
  • Mollies can grow up to 3 inches which is larger than bettas. Because of this, it’s not recommended to put them in tanks smaller than 20 gallons.
  • Mollies can live up to 5 years but it’s more common for them to only live 1-2 years.
  • One of the most important things to take into consideration is the fact mollies are live bearing fish. You need to have an effective plan to deal with the fry if you add female and male mollies to your betta tank.
  • Mollies and bettas have similar diets, so you can add the same food in the tank for both of them to eat.
  • Mollies are rarely aggressive and are more likely to attack each other in order to establish a hierarchy. However, occasionally they may nip fins.
  • Avoid adding balloon mollies to your tank because they are selectively bred to have scoliosis.

If you have any more questions you can leave them in the comment section below, otherwise why not check out some more articles on betta tank mates!

    • African Dwarf Frogs & Bettas – You don’t just have to have fish in your tank with bettas. A lot of people choose to add African dwarf frogs, They’re an interesting animal for any aquarium and they can coexist peacefully with your betta!

    • Tetras As Tank Mates – Tetras are one of the staple fish you find in almost every aquarium and no wonder. They are extremely easy to keep and make great tank mates. Find out what you need to do to make your aquarium a fitting home for your tetras in this article!

    • Do Guppies Work? – You may have been told that you can’t keep guppies with your betta. While there is some truth to this it’s not the whole truth. Read this article to find out how and why you can choose to keep guppies!

    • Snail Tank Mates – While they’re not as exciting as some of the other choices, they are a great choice. Not only will they coexist peacefully with your betta, but they’ll also help to keep your tank clean. (Just watch out for over breeding.)

    • Platies And Bettas – Platies are one of my favorite fish and they’re one you should definitely consider. Another livebearing breed, platies make any aquarium a little bit brighter with their color and personalities!

Ultimate Betta Fish Care Guide
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