Can Mollies and Guppies Live Together?

Most people want their aquarium to be a peaceful corner in their household.

For this reason, they prefer to keep fish that can coexist together and do not engage in many fights.

In this article, we will talk about whether mollies can live together with guppies in the same tank.

We will also give you some useful insights about the types of guppies and mollies that exist and the best tank mates for them!

Can You Put Mollies and Guppies in the Same Aquarium?

Mollies and guppies are both very similar in nature.

They are both livebearers, which means that they do not lay eggs but give birth to baby fish. They are both very peaceful and highly compatible.

They even have the same feeding requirements! Hence, it is totally fine for mollies and guppies to live together in the same tank under the same conditions.

Similarities between Mollies and Guppies

Mollies and guppies are a great fit as they have the same types of behaviors and needs. They share common genes called Poecilia.

Both breeds belong to the same species of fish that have many different breeds.

Guppies and mollies are both very easy to look after. They enjoy surviving independently and are very low maintenance, so you don’t need to check up on them regularly.

However, mollies are a bit aggressive. They tend to attack fish that have long fins like guppies.

Since guppies belong to the same fish family as mollies, they are less prone to the attack on their fins by mollies.

Mollies and guppies also have very similar interests. They like to nibble on plants, eat a small amount of food, wiggle their bodies, and breed.

Both breeds like to live in slightly salty water. They are usually very social with other fish of their breed and like to stay active throughout the day.

Types of Guppies and Mollies

Let’s have a look at different types of Guppies and Mollies that you can consider keeping in your fish tank.


Guppies are beautiful freshwater fish that add vibrancy to your fish tank. An average domesticated guppy fish is only about 2 inches long.

Guppies like to explore and swim around a lot, which is why they need an ample swimming space. A small 10-gallon aquarium is suitable for guppies.

They enjoy a temperature of 73 to 80 degrees Fahrenheit and water with a pH of 6.7-7.7.

Common types of guppy fish that differ in their patterns, color, and fin types are as follows:

  • Leopard guppies
  • Lace guppies
  • Moscow guppies
  • Grass guppies
  • Mosaic guppies
  • Sunset guppies
  • Tuxedo guppies
  • Cobra guppies
  • Snakeskin guppies
  • Koi guppies
  • Red-eye guppies


Molly fish are almost twice the size of an average guppy fish— they are around 4 inches long. A 20-gallon aquarium is needed for them to swim around.

Hence, if you are keeping guppies and mollies together, you will need a 20-gallon tank. It will give ample space to guppies and just the right space to mollies.

The ideal water requirement for mollies is 76 to 85 degrees Fahrenheit, with a pH of 6.8-8.8.

The most popular types of molly fish that can be kept in an aquarium are:

  • Ballon molly
  • Dalmatian molly
  • Potbelly molly
  • Black molly
  • Golden lyretail molly
  • Green sailfin molly
  • Gold latipinna molly

How to Keep Guppies with Mollies

Here are some tips to help you keep guppies and mollies together.

Add Plants to Your Aquarium

Mollies and guppies both enjoy nibbling on plants. Since mollies are larger than guppies, they tend to eat more and enjoy plants in particular.

When these breeds give birth to their fry, plants provide a hiding space for them. Plants also oxygenate the water in the tank and help keep the tank clean.

Add a Filter and a Heater

Guppies and mollies both like to live in warmer temperatures. They will not respond well to sudden temperature changes.

Mollies, in particular, can be aggressive. Adding a heater to your tank will ensure that the temperature stays regulated.

You must also add a filter to your tank, especially for the molly fish. Mollies eat a lot; hence, they also excrete a lot. This can pollute the water in the tank. You must add a filter to prevent this from happening.

Choose the Right Aquarium Size

You might get away with having a small aquarium if you are just keeping guppies, but you need to invest in a larger tank if you are also keeping mollies.

A tank with a capacity of at least 20 to 25 gallons is sufficient to keep both guppies and mollies together. The bigger the tank, the larger space for your fish to move around and be active.

A larger aquarium will also give the fry plenty of room to hide from the big fish.

Do Not Add Too Many Males

Like other livebearer fish, mollies and guppies love to breed. As long as there are males and females both in the tank, you will continue witnessing the birth of many new fry.

It is recommended that you keep only male or female fish to stop any unwanted breeding.

Both mollies and guppies tend to eat their fry, so you must separate them as soon as they give birth.

Avoid Overfeeding

Mollies and guppies have a large appetite, but that does not mean that you feed them each time they appear hungry to you.

Adding too much food to the aquarium can result in too much waste.

It can also cause water to start smelling. Giving excess food can also cause digestive problems and constipation.

Cross Breeding Between Mollies and Guppies

As mentioned before, mollies and guppies share the same genes, much like tigers and lions. Even though they prefer reproducing with their own breed, it is not uncommon for them to breed with one another.

Since mollies and guppies are quite similar, it is not surprising that they can crossbreed.

The fry produced by guppies and mollies usually dies at a young age. Very rarely does a crossbreed fish make it to adulthood.

These adult crossbred fish will be infertile and unable to reproduce further.

Both mollies and guppies can carry sperm in their bodies for several months, even after they have given birth.

This is why it is recommended that you keep all-male fish if you want to avoid breeding altogether. There is a high chance that any female fish you buy might already be pregnant before you bring it home.

If you end up with a lot of fry, separate them from the adult fish immediately before the adult fish can devour them.

Keep the fry in a separate tank or sell them to your local fish store in return for store credit to buy food and equipment for your adult fish.

Feeding Guppies and Mollies

Guppies and mollies eat the same type of food, so if you keep them together, you are in luck! Both breeds enjoy a plant-based diet but do not have a sense of what they should or shouldn’t eat.

Hence, you must avoid giving them food that can harm their health.

You can feed mollies and guppies live food, cooked vegetables, and frozen foods like blood worms. You can also add vegetable pellets, flakes, and freeze-dried food to add variety to their diet.

You don’t need to feed mollies and guppies very often. Feeding them once a day is enough. Remember to avoid overfeeding. It not only pollutes the tank water but can also cause health problems for your fish.

Both mollies and guppies like to feed on algae. Mollies are bigger algae eaters than guppies. If you see algae developing inside your tank, do not worry; your molly fish to devour it!

5 Best Tank Mates for Guppies and Mollies

Here are the best tank mates that you can keep when keeping both guppies and mollies in your fish tank.


Swordfish has a very calm temperament. They get along with almost all other freshwater species.

They stand out from other fish because of their appearance and can add uniqueness to your aquarium.

They can adapt to several water conditions and require around 20 gallons of water, just like mollies.


Platies are also freshwater fish that come in many different sizes, shapes, and colors. They are peaceful little creatures that are very easy to care for.

Like guppies, they tend to reproduce a lot, so keep male fish to avoid any unwanted breeding. They tend to eat the same food as mollies and guppies do, making them excellent tank mates.

They also require the same amount of tank water as mollies do to swim around.


Tetras are neon-colored freshwater fish that can add variety to your aquarium. Like mollies, they also like nipping on the fins of other fish, so be careful not to aggravate them.

Like other livebearers, they enjoy breeding and can produce many unwanted fry with guppies that you must take care of.

It is usually recommended to keep tetras in groups of 7 or more with a tank capacity of at least 30 gallons.


Gouramis are the most sociable species of fish that are loved by many fish owners.

They are brightly colored and have many unique patterns on their little bodies. They also have a longer lifespan and can live for more than 4 years.

However, gouramis require more care than mollies and guppies. They require plenty of shade in the fish tank. You can use floating plants to accomplish that.

Gouramis also need adequate hiding places. As long as you are willing to take care of them, you can certainly keep them with mollies and guppies.


Even though they do not classify as fish, snails can be a great addition to your aquarium. They mind their own business, require very few gallons of water, and have a long life expectancy of 1 to 2 years.

They help keep the tank clean since they feed on algae and other waste.

You can choose from many different kinds of freshwater snails such as mystery sails, nerite snails, apple snails, and rabbit snails.

Final Words

So, if you want to keep your mollies and guppies together, wait no further!

Both breeds have very similar personalities and needs and can thrive well in each other’s company.

Add them to your aquarium and create a diverse environment that your dear little creatures can survive well in!

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