Can Molly Fish Live Alone? Can You Keep A Single Molly In Tank?

If you have ever owned a pet fish, you are no stranger to the joys of watching your little aquatic friend swim around and explore their tank. Molly fish are some of the most popular freshwater fish in the aquarium trade, and for a good reason. They’re cute, they come in a variety of colors, and they don’t require much maintenance. However, many people have questions about whether or not it’s possible to keep just one Molly alone. Can a Molly Fish live alone? Can you keep a single molly in a tank?

No, molly can not live alone, and it’s not a good idea to make it all lonely in the tank. It is a social fish that prefers to stay in a group of at least six mollies and cannot survive alone in the tank for long. When you keep molly fish alone in the tank, these fish will suffer from loneliness, stress, various diseases, and illness.

You have to handle the passive aggressiveness and withdrawal syndrome that comes with loneliness and poor socialization in molly fish.

Moreover, if this fish has your attention and wants to know more about it, it is the right place for you. Hopefully, this article will answer all your questions.

Can Molly Fish Live Alone?

If you are asking if a molly fish can live alone, then the answer is yes. However, to have more color variety in your tank or aquarium and make it look prettier for viewing purposes, some people prefer not to put any other fish with the mollies. But it is not a good idea to keep your social, outgoing, schooling fish alone in the tank.

However, some people do not like to put any other fish with the mollies. They consider their fish to be fragile and get anxious very quickly.

And a Molly can live on its own as long as it has the correct setup and environment, but this is not a good idea.

They are fish that needs to live in groups of more than one. This is because they need the company of other mollies, and if kept alone for too long, they will become stressed and depressed.

But Mollies are also territorial fish, so it’s important to give them sufficient space in their tank or aquarium and not overcrowd them with other fish.

Can You Keep A Single Molly In A Tank?

The answer to this question is not a simple one. Yes, but many things come into play when considering the care needs of your single pet fish and how much time it will need from you daily.

Some people succeed with just one Molly if they’re willing to be very careful with their water quality and closely monitor the fish’s diet.

Your Molly Fish should have a tank of at least 30 gallons to maintain good water conditions and provide plenty of swimming space.

However, one problem arises when considering whether or not to keep just one Molly in a tank that size. And don’t even think about keeping molly fish in a fishbowl.

Usually, pet store owners keep Mollies with other fish and sell them in a group of six Mollies. This is because they need the company to thrive and will be lonely if owned by themselves. But, then, it might not be a great idea to keep just one Molly in a tank that size.

Why Should Not You Keep A Single Molly In A Tank?

A single Molly will be lonely and depressed, making them more susceptible to disease. They are very social fish that need the company of others to thrive.

This means keeping a few in your tank or even just one other Molly for best results. It would help if you did not keep Mollies with predatory species from their genus, such as Platy, because they may eat these weaker fish.

The canaries, guppies, swordtails, or platies all do well together, but no matter what, it is important you have at least two.

It would be best if you did not keep Mollies with predatory species from their genus, such as Platy’s or Canaries.

They are also hardier than other live-bearing fish and can survive in colder water, but this isn’t optimal. Mollies do best between 72 degrees Fahrenheit to 82 degrees Fahrenheit, the average home temperature in most homes today. Also, you must avoid keeping a single molly because they need the company of others to thrive.

What Happens When Molly Fish Live Alone In The Tank?

Mollies are easy-going, peaceful fish that usually get along with their tankmates. However, they will become isolated and unhappy if raised alone and should have at least a few other mollies in the same tank. Therefore, it is better to keep Mollies with others of their kind and do best when kept in groups.

Some of the consequences of keeping Molly fish alone are:


Have you ever met an extrovert, or are you one? What do you think they will do when alone in the whole world?

Human beings are social animals, and they crave human contact. Hence, the same applies to your molly fish which is quite social and outgoing.

Don’t you know your molly fish is a schooling species that prefers to stay with 5 or 6 other molly fish?

When you keep molly alone, it will become lonely and search for company inside the tank. Can you feel the turmoil of being alone in the whole tank?

The cravings for contact from other mollies, the missing play date, and the whole ‘swimming together in a school’ escapades break your molly’s heart.

Mollies belong to the same family of shoaling fish that live together in groups. The risk of loneliness increases when only one individual lives inside an aquarium.

Molly Fish are social animals who prefer to spend their time with other individuals of their species rather than getting too close to humans or being alone for long periods. If they lack interaction with others, they may become withdrawn, passive, or aggressive.

Behavioral Problems

Leading a solitary life can have adverse effects on the behavior of some fish. For example, male fish confined to individual containers underwent dramatic personality changes: molly fish became more aggressive and less social than those housed with others.

These behavioral differences occur due to the absence of certain chemicals or hormones produced only when animals, interact-including serotonin, dopamine, and vasopressin.


Some freshwater aquariums require many hours each week for maintenance, such as water testing, cleaning filters, and adding new fish food. The time it takes for care is often too high for people living alone without outside assistance or help from other family members. This may cause feelings of stress and anxiety.


Fish who live alone for extended periods may experience loneliness, depression, or boredom. This can cause them direct harm by making it difficult for the fish to interact with other animals in their environment.


Some diseases are contagious among freshwater aquarium species, such as Ichthyophthirius multifiliis (Ich).

Fish from one tank infected with this parasite can spread it into another nearby tank through water currents. This could eventually kill many fish in a community setting.

Also, have you ever thought about the mental health of molly fish? Yeah, I know people often think their fish won’t feel a thing, but trust me, your molly has feelings, and loneliness is something that can hurt their feelings to the extent of heartbreak.

You have to handle all the depression, withdrawal, aggression, etc., that comes with loneliness. Yeah, people might not consider this a disease, but all of this result in not eating their food and staying in one place with no movement.

Hence, the absence of food and an active body will make your molly fish prone to various physical illnesses. You might even find your molly fish struggling to breathe, hence the respiratory problems, another molly fish disease.


The risk for injury increases when only one individual lives in the tank. The risk of injury from a fish tank’s sharp edges and corners increases when only one individual lives inside. A sharp edge in the tank can easily slice the fish.

Benefits Of Keeping Molly Fish In Groups

It is not uncommon for molly fish to keep groups of more than six, with some even keeping as many as 20 mollies together. Some of the advantages of keeping Molly fish in groups are:

  • First, they are more likely to support each other company.
  • Second, tankmates can help fight off illnesses and other problems due to overcrowding or lack of space in the tank.
  • Finally, there is less chance for bullying as they have companionship, so it’s easier for them not to bother their tank mate(s).

If you want your Molly fish to live happily alone in a tank with other types of fish, be sure that the temperature matches up and that there are plenty of hiding spots.

Best Tankmates For Molly Fish

Molly fish are the best beginner fish for aquariums, making them popular among aquarists. They can live in groups of one or two individuals.

However, it is not a good idea that they share an aquarium with other species. Still, the most suitable tankmates for Molly Fish include:

  • Guppies
  • Platys
  • Mollies
  • Neons
  • Corydoras
  • Goldfish
  • Swordtails

It would help if you kept them with other docile fish species, such as the Cardinal Tetra. Read here to know how you can keep molly fish with guppies.

Best Plants To Keep With Molly Fish

It is important to keep in mind this will change depending on your environment, and you should always research before adding a new fish into an aquarium.

Your mollies might not prefer a densely planted tank, but they will love a tank with many plants to play and hide around.

Some of the plants that you can keep in the molly fish tank are:

  • Java fern
  • Moss balls
  • Anubias 
  • Nana
  • Petite nana
  • Neptune grass (also called red tiger lotus)

How Can You Maintain The Tank Of Molly Fish?

Maintaining the ideal water parameters in the tank for a Molly Fish is easy. First, make sure that you clean it about once every week and replace some water. It’s important to do this so that all the waste from your fish doesn’t accumulate, which will cause an unpleasant smell and illness for your pet.

Moreover, some tips that can help you to manage the tank of Molly fish are:

  • Change the water every couple of days
  • Clean off algae as soon as possible with a sponge or an algae pad. However, be careful not to remove too much – just enough to not grow back quickly.
  • Feed once per day and feed according to the instructions on the food packaging
  • Add new plants when you need them.
  • Add a heater if your tank is in an area with low temperatures
  • Ensure weekly maintenance on the air pump, filter, and water conditioner.
  • Clean the tank at least once a month thoroughly.
  • Feed your fish live food, along with flakes or pellets. Don’t you know how your molly fish eat pellets?
  • Keep a close eye on the water level and make sure it’s high enough for them to swim around comfortably. If you notice that some of your mollies are lying down in an area with no water, add more water.
  • Keep the tank leveled off so they can’t jump out of it.


In conclusion, you can keep one Molly in an aquarium with other fish species as long as they are not aggressive towards the mollies, and it will be alright to have only one male in the tank at once since males tend to show less aggression than females do. They might try to spawn with other fish species, but it is not likely.

Mollies are social creatures, so they would do better in a group rather than being alone all the time. However, keeping more than one Molly might be stressful for some individuals, and you should make sure that your aquarium has plenty of hiding places, plants, etc., to prevent this from happening.

Hopefully, this article has given you some insight on can Molly fish live alone. Please drop them in the comment section below if you have any questions or queries. Thank you!

Good Luck!!

Happy Fishkeeping!!