Can Betta Fish Live With Mollies? (are they good tank mates?)

Betta fish are often thought of as solo specimen fish that need to be kept alone. That couldn’t be further from the truth. There are lots of really good tank mates for Bettas.

I think it is true to say, with the exception of Guppies, I have kept and bred more Mollies than any other fish. I find myself fascinated by the way Mollies conduct themselves in the aquarium. I currently keep a number of different Molly strains in tanks with Bettas.

Yes, Betta fish can live with Mollies. Mollies make excellent tank mates for Betta fish. Both species of fish want to live in similar water parameters and both Bettas and Mollies want to eat the same type of foods.

Can Betta Fish Live With Mollies?

In my experience, Bettas and Mollies make excellent tank mates. Whether it’s Black Mollies, Sailfin Mollies, Gold Mollies, or Dalmation Mollies, I have kept them all with Bettas over the years, and they have all been tanks that worked out well.

Will Bettas Chase Mollies?

In my experience no, Bettas won’t chase Mollies. The smaller members of the Molly family, like the Black Mollies, are fairly fast swimmers and can easily swim faster than a Bettas, especially a long-finned Betta. Larger Mollies like Sailfin Mollies are very strong swimmers, and again a Betta is no match for their speed.

Bettas will however chase and catch baby Mollies. See more about this below.

Will Mollies Nip a Bettas Fins?

Again, in my experience, no Mollies won’t nip at the Bettas fins. I have several tanks with a Betta and Mollies living in them and all those Bettas have flawless, flowing fins.



What Types of Molly Fish Can Live With a Betta?

I think just about every member of the Molly family can live in the same aquarium as a Betta. Over the last few years, I have tried many combinations, and every combination has broadly been a success. Below I have listed some of my favorites.

Black Mollies

Black Mollies work really well with Betta fish. The all black color of these Mollies seems to really boost the color of the Betta.

Black Mollies are broadly peaceful and will take little notice of the Betta. Black Mollies are prolific breeders, and some of their many offspring will provide vital nutrients to the Betta who will undoubtedly consume a fair number of them.

Black Mollies are voracious algae eaters and so they will help keep a Betta tank clear of algae, especially hair algae, black beard algae, and string algae.

Gold Dust Mollies

Gold Dust Mollies work really well with Betta fish. I find the red and blue Bettas really stand out against the gold and black bodies of Gold Dust Mollies.

Much like Black Mollies, these peaceful fish will keep themselves to themselves when kept with a Betta and their desire to eat algae makes them a bonus addition to many tanks.

Sailfin Mollies

Sailfin Mollies are a little larger than Black Mollies, and the males, in particular, have impressive dorsal fins (hence their common name).

Many aquarists add salt to their Sailfin Molly, tanks, but if you are keeping a Betta with the Sailfin Mollies I would advise against using salt as the Betta will not appreciate it.

Sailfin Mollies have large appetites and they can swim fairly quickly when food is in the water, so make sure they don’t outcompete your Betta for food.

Dalmation Mollies

The silver background color of the Dalmation Molly will contrast amazingly against almost any color Betta. I have always found Dalmation Mollies to be extremely active in the aquarium.

I also find Dalmations Mollies to be one of the most variable Mollies when it comes to color. Some are almost completely silver, others are almost black, and there is every combination in between.


Will a Betta Eat Molly Babies?

Yes, a Betta will easily and quickly eat Molly babies. Depending on which side of the fence you stand, this can either be considered a positive or a negative.

Clearly, if you are actively trying to breed your Mollies to increase the size of your population, you don’t want the Betta to be eating the Molly babies. In this instance, maybe consider housing your Betta somewhere else.

If you like the thought of a few Molly babies surviving, but you aren’t actually trying to breed your Mollies for a profit, then you can set your tank up in such a way a few Molly babies will probably survive.

By providing lots of hiding spaces you create lots of places the babies can hide out whilst they grow. I like to fill my Molly tanks with live plants. These plants not only help keep the water clean and clear (more on that below), but they also provide lots of hiding spaces and line of sight blocks. If the Betta can’t see the babies, he won’t try to eat them.

I have also used piles of rocks and aquarium-safe wood to achieve the same result. Essentially, to help some Molly babies survive you need to make places they can go where the Betta can’t.

Finally, if you are in the camp that likes keeping Mollies, but doesn’t necessarily want more babies, a Betta is a fantastic way to control the population. Bettas have been used to control Guppy populations in tanks for many, many years.


What Size Aquarium for a Betta and Mollies?

Mollies, especially Sailfin Mollies, tend to be larger, and more active than Bettas, and as such will require a slightly larger tank.

The minimum size tank I would consider keeping a Betta with a small group of Mollies in would be a 20-gallon (76 liters) tank. As always, bigger is better, so don’t scrimp on size if you don’t need to.

I currently keep a small number of Black Mollies in a heavily planted 20-gallon (76 liters) tank and it is full of movement.

How Should a Betta and Molly Tank be Set Up?

Neither Bettas nor Mollies are especially fussy about how their tank is set up. Both fish like a bit of open swimming space and both look amazing against a background of live plants.

I have used various different substrates in my Betta and Molly tanks over the years. At the moment, I think this sand I ordered from Amazon is my go-to choice. It looks great and the minerals that will slowly dissolve into the aquarium water will really be appreciated by the Mollies.

As mentioned above, I like to add lots of rocks and pieces of aquarium-safe wood into my tanks. The piles I create make an excellent line of sight block, which apart from anything else, allow female Mollies to get away from the males when they don’t want the attention.

In my opinion, live plants are another great addition to a Betta and Molly tank. Live plants don’t just enhance the natural feel of the tank, but they also absorb some of the fish waste as they grow. The water is almost always cleaner and safer for the fish when live aquarium plants are growing.

One of my own 155-gallon planted tanks

There is a wide range of plants you could use in a Betta and Molly tank. Some of my favorites are;

To find out more about any of these plants, take a quick look at WetPlants.com website.

How to Filter a Betta and Molly Tank?

Whilst Mollies are generally considered strong swimmers and can cope with a fair amount of flow in the tank, Bettas are not so strong. An appropriate filter should be chosen to ensure the Bettas lifespan is not reduced due to continually having to fight the current.

In my experience, hang-on-back filters give the best balance between filtering and good water turnover without blasting the fish around. I have had great success using the C-Series hang-on-back filters which are made by Fluval.



Water Parameters for a Betta and Molly Tank?

Although Bettas and Mollies come from very different parts of the world, both fish are adaptable and hardy and can tolerate a wide range of water parameters. I have found that keeping my tank within the following parameters leads to a happy, healthy tank.

  • Temperature: 72°F – 82°F (22°C – 28°C)
  • pH: 7.0 – 8.2
  • Hardness: 6-12 °GH/100-200 ppm
  • Ammonia: 0ppm
  • Nitrite: 0ppm
  • Nitrate: 40ppm or less

If you are unsure of the pH of your Bettas tank, I would strongly recommend testing it using an aquarium test kit.  Personally, I use the Freshwater Master Test Kit which is made by API.  It is fairly accurate and simple to use. I just bought this one on Amazon.


What to Feed a Betta and Molly Tank?

Luckily, Bettas and Mollies essentially want to eat the same foods. Bettas primarily want to eat their food either from the surface or high up in the water column. Mollies on the other hand will eat from just about anywhere in the tank.

I have had good success feeding pellet foods like Bug Bites which is made by Fluval and VibraBites which is made by Hikari. Both foods are made with quality ingredients and both are floating or slow sinking, making them ideal for both Bettas and Mollies.

Unlike a Betta, Mollies want to eat some vegetation, usually in the form of algae, so consider adding a mixed flake to their diet. TetraMin Tropical Flake is a good quality balanced flake food and Omega One Veggie Flakes are high in algae.

To make sure the Betta and Mollies get a complete range of nutrients they need, consider feeding some live or frozen food to them. Both species of fish will go crackers for live or frozen bloodworms, daphnia, or brine shrimp.


What Other Fish Can Live With a Betta and Mollies?

There are lots of other fish that can live in a Betta and Molly tank. Over the years I have kept several setups with a Betta and Mollies, and below I lost some of my favorites.

Guppies

Guppies work well in just about every community tank scenario, and a Betta/Molly tank is no exception. Guppies come in an almost endless range of colors, and a strain can be chosen to match or contrast the colors of the Betta.

Guppies want almost identical water conditions to Bettas and Mollies and they will eat the same foods.

As mentioned earlier, Bettas are a great way to keep a Guppy population under control, so adding a Betta to a Guppy tank will help prevent the population from exploding.

Cherry Barbs

Cherry Barbs are another great addition to a Betta and Molly tank. Cherry Barbs are active little fish that bring lots of movement to a Betta tank.

As their common name suggests, Cherry Barbs are a bright pink color with the males being especially colorful. Due to the fast swimming ability, care should be taken that the Cherry Barbs don’t dominate all the food.

Bristlenose Pleco

I believe every community setup should have a Bristlenose Pleco in it. These fish are peaceful bottom dwellers that spend their entire day either tucked up in their cave or roaming around the tank looking for food or algae to eat.

Bristlenose Plecos are so valuable in a Betta/Molly tank because they will keep the glass, rocks, and decorations free from algae.

Panda Corydoras

Panda Corydoras are one of the smallest members of the Corydoras family. Panda Corydoras spend all their time rooting around in the substrate looking for food. They are great at clearing up any uneaten food that makes it past the Betta and down to the substrate.

Because Panda Corydoras stay so small they are perfect for even a very small Betta tank. A 20-gallon tank with a Betta, 5 or 6 Mollies, and a handful of Panda Corydoras will be a fabulous setup that you will never tire of watching.

Rummy Nose Tetras

Rummy Nose Tetras are another fish that I have in several of the tanks in my fish room. Rummy Nose Tetras are very active and require a slightly larger tank. If you are thinking about keeping your Betta and Mollies in a 40-gallon (150 liters) or larger, Rummy Nose Tetra would be a great addition.

Kuhli Loaches

Kuhli Loach are small, nocturnal fish that make an excellent clean-up crew for a Betta/Molly tank. Kuhli Loaches are small, strippy fish that come out at night and root around the entire tank looking for anything leftover food to eat.

Kuhli Loach are one of the hardiest species of fish in the hobby and they are especially tolerant of the kind of mistake new fish keepers sometimes make.

Other Tank Mates

There are many other species of fish that could be kept in a tank with a Betta and a group of Mollies. Below I have listed some you might like to try;

  • Cardinal Tetras
  • Harlequin Rasboras
  • Ember Tetras
  • Albino Corydoras
  • Platies


In Conclusion

I have kept Betta fish with Mollies on many occasions, and it is a combination that works really well. Whether you keep Black Mollies, Gold Dust Mollies, Dalmation Mollies, or Sailfin Mollies, the basics are the same. Feed the tank well, keep the water clean and watch out for any aggression.

Hopefully, this will be a setup that brings many years of enjoyment.


About the Author

I’ve been keeping, breeding, and showing tropical fish for nearly 30 years. Over that time I’ve done it all! I’ve had great success and I’ve made some really foolish mistakes (like the time I bought an Asain Walking Catfish). Read more…
Richard James
Editor