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Can Bettas And Mollies Be Good Tanks?

bettas and mollies

Betta fish are known to be aggressive and territorial in nature. Because of its lousy temperament, it is hard to find an appropriate tank mate for your betta fish. Some fish are compatible with your betta fish. So are bettas and mollies compatible with being tank mates?

To answer whether or not bettas and mollies are compatible enough to be tankmates, the answer is yes. It is possible to keep a betta fish and a molly together as long as its temper and the tank parameters are kept in check. The only problem you might face is that of the dilemma involving the use of saltwater or freshwater.

Bettas And Mollies – Compatiblity Factors

betta and mollies

Water Temperature

Fortunately, there is sufficient overlap between the water temperature requirements of both fish. Betta fish need water that is between 76 and 82 degrees Fahrenheit. Mollies, on the other hand, require water temperature ranging from 68 to 82 degrees Fahrenheit.

As a result, both bettas and mollies like swimming in warm water. As long as the temperature is appropriate for the betta fish, it will be optimum for both fish. However, if the water temperature in the tank is outside of the optimum range, the fish may become stressed.

Water pH Level

Betta fish require a pH level of about 7 in their water. A molly, on the other hand, requires a pH range of 7 to 7.8. Thus, it is pretty evident that both fish like neutral water conditions. As a result, keeping the pH at a neutral level of 7 is ideal for both fish.

You should check your tank’s water pH level periodically to make sure it is neutral. A molly can survive slightly alkaline water. But it is recommended to keep the water pH close to 7 so that the fish do not get stressed.

Tank Requirements

mollies thrive better

If we talked about the required tank size to keep the bettas and mollies together, you first need to consider each fish’s requirements. A betta fish needs at least 2 to 5 gallons of water to thrive. A molly, on the other hand, requires a tank size of about 5-6 gallons.

Thus, it is pretty evident that a tank size of a minimum of 10 gallons is required to keep bettas and mollies together. However, it is always recommended to get a bigger tank than the minimum requirement, especially in the case of a betta fish.

It is said that mollies thrive better in saltwater, while bettas like freshwater. You have no reason to get worried because of this disparity. Some people have suggested adding aquarium salt to a betta tank as it increases the immunity of the betta fish.

You also need to add a sufficient amount of decor in your betta tanks like plants, driftwood, and caves. This not only makes your tank look attractive but also ensures that your betta fish has good places to hide in the tank.

Food Requirements

Bettas and mollies have similar diets, which is another reason to keep them in the same tank. Mollies are more of omnivores eaters, while a betta fish is a carnivore in nature. The only thing to remember is to give both your fish a balanced diet.

Thus, a betta fish’s diet is more meat-oriented, while a molly balances plant and meat-based diet. An ideal betta diet consists of quality betta pellets, betta flakes, bloodworms, daphnia, and frozen brine shrimp. Mollies can sometimes eat algae too.


As stated earlier, a betta fish is quite aggressive and territorial in nature. However, this varies from betta to betta. Thus, some betta fish may be more aggressive than usual, while some may be relatively peaceful. The same goes for the mollies, but in this case, mollies are pretty friendly.

Aggression can be seen on the part of the mollies only in case there are more than one male mollies in the tank. A male betta fish is more aggressive than a female betta fish. Thus, you have got a better chance of putting together a female betta fish with the mollies.

However, in the case of female bettas, you need to put them in sororities. This will require a larger tank. As long as all the necessary conditions are met, you will not face any problems or aggression from the betta fish towards the mollies.

Bettas And Mollies: Types Of Mollies


You can keep a whole range of mollies with your betta fish. Here are some of the most suitable picks.

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

FAQs on Keeping Bettas And Mollies Together

How many mollies can I keep with a betta fish?

In a 10-gallon tank, you can keep up to 3-4 mollies with your betta fish. However, this depends on the type of mollies. Larger breeds need larger tank sizes. Thus, if you keep bettas and mollies together, get a tank more significant than 10 gallons.

Are molly fin nippers?

YES. Mollies have been seen to nip fins from time to time. Thus, keeping bettas and mollies together may be an issue unless you get a tank large enough to provide each fish with sufficient space to swim freely.

How long do mollies live?

Mollies are said to have a lifespan of about five years. However, in a tank, their life span is about two years if proper care is provided.

Final Thoughts

Thus, if you think of keeping bettas and mollies together in one tank, you can undoubtedly go for it. Just make sure that all the required tank conditions are met properly. In the end, it all depends on the temperament of your betta fish.