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How Many Mollies in a 10 Gallon Tank? (Read This First!)

Molly, sometimes known as short-finned molly, are well-known all over the world for their intriguing and engaging behavior in aquariums. They are primarily black, white or silver in appearance.

The females are larger than the males. The difference in size between them is 12 to 8 cm. From Mexico to Columbia, these species can be found in freshwater, occasionally in coastal water, and sporadically in marine water as well.

Mollies are one of the most popular choices among eager aquarists due to their fast development rate, large birth size, reproduction, and large brood size.

Let us have a detailed discussion on how many mollies can live in a 10-gallon tank and also discuss some fascinating facts about the nature of mollies.

How many mollies in a 10 gallon tank?

In a 10-gallon tank, you can keep 2 to 3 mollies together. Adult mollies usually grow to about 3 to 5 inches in length. Therefore, one molly requires at least 3 gallons of water to swim freely in a tank. As a result, three mollies live happily and comfortably in a 10-gallon tank without any hassle.

The number of mollies can differ according to species. Let’s get to know how many of them you can keep them together.

Black mollies:

Black mollies are among the most common mollies that are widely available in almost every continent of the world.

As they are quite common around the globe, the black mollies are also referred to as the “Common Molly”. Besides, they’ve got other nicknames too.

For instance, they usually have cute, short black fins. Thus, they are also known as ‘The short-fined molly’ by many. Speaking of black mollies, you will notice that they only have one color all over their bodies, and that is, the color black.

Many might think that it’s totally a genetic thing. But, there are some other factors responsible for it as well. Black mollies have a serious genetic condition which is known as melanism.

For being born with severe cases of melanism, the black mollies don’t have any color pigmentation in their bodies.

As a result, they are born black and sometimes have slight linings of either yellow or silver on their dorsal fins, tails, or flanks.

They simply love to live in colonies. Thus, it is quite convenient for the three mollies to live together in a 10-gallon tank.

Dalmatian mollies:

Dalmatian mollies are the most active, social, and playful of all molly species. They are calm and peaceful fish, which are very easy to handle and nurture if provided with the proper diet and environment.

They have an awesome color combination of black and white on their entire bodies. As a result, they are quite often referred to as Dalmatian dogs for having this color combination.

Sometimes they are gray in color with black spots on them as well. Moreover, there are other varieties of color combinations that have been found among the ever-versatile Dalmatian mollies.

Compared to the regular mollies, the Dalmatian ones are a bit larger in size. They are nearly 4 to 5 inches long. They like to live in colonies as they are quite social in nature.

But, in a 10 gallon tank, it is better to keep 2 Dalmatian mollies together as they tend to grow up to 5 inches and sometimes more than 5 inches.

Keeping only two Dalmatian mollies in a 10-gallon tank together would be helpful in providing them with an adequate swimming area to stay comfortably in there.

Balloon mollies:

Balloon mollies are another favorite choice for aquarists when it comes to choosing the most top-notch fish for their aquariums.

Just like other mollies, they also love to live in communities, maintaining social relationships with other tank mates as well. It is recommended to keep 4 balloon mollies in a 10 gallon tank.

Can mollies live in a 10 gallon tank?

Yes, mollies can undoubtedly live in a 10 gallon tank. Molly fish may be kept in a variety of tank sizes without any possible difficulties. They usually require small places to live in. This is why a molly’s minimum tank size might be as little as a 10 gallon tank.

As mentioned earlier, 2 to 3 mollies can easily live in a 10 gallon tank. But not all mollies and their vast variety of species grow to the same shape and size.

Therefore, these numbers can vary depending on the species of molly that you are keeping in your 10-gallon tank.

The male mollies might become quite aggressive in the mating season. Therefore, to maintain a perfect balance, it is highly recommended to keep one male and two female mollies together in a 10 gallon tank.

Are mollies good for a 10 gallon tank?

Yes, a 10-gallon tank will suffice for the mollies. Mollies usually require a very small amount of space to live in as they are quite small in size.

A minimum tank size of a 10 gallon tank is big and good enough for the mollies. Now, let us feed your hunger for knowledge on this and discuss some of the most solid reasons why a 10 gallon tank is good enough for the mollies. 

Here are some of the most convincing reasons for the following: 

Mollies are typically small in size:

Mollies are typically small. On average, they reach a length of 3.85 to 4.75 inches and are not more than 5 inches. This is one of the primary reasons why mollies require such a small amount of space to live on.

Therefore, this is one of the most significant reasons why they can live well in a 10 gallon tank.

Mollies need a small swimming space:

A molly only requires a swimming space of 3 gallons in the entire tank. So if you kept three mollies together, they would only need 9 gallons of swimming space.

So, when you are keeping them in a 10 gallon tank, they are getting another extra gallon to explore as their swimming space additionally.

Thus, this is another solid reason a 10 gallon tank is a perfect choice for keeping your cute little mollies.

How many of these fishes can live with mollies in a 10 gallon tank?

Mollies are one of the most tranquil pet fish readily available nowadays. This is why they are often referred to as “calm communal fish.” They love to live with numerous fish of the same species since they are gentle.

It’s also clear that they get along with other fish of the same species quite easily, as they are very social in nature. Guppies, tetras, platies, and a variety of other fish are commonly housed together in the same tank as the mollies.

These fish live in peace and harmony together. You might be wondering how many of these fish can live in a 10 gallon tank with mollies.

In a 10 gallon tank, the following is the maximum number of fish that may coexist with mollies, and those are discussed below:

Mollies and Guppies:

In a 10 gallon tank, you may keep 4–5 guppies with mollies. Guppies, like mollies, are normally peaceful fish. They also don’t take up a lot of room.

You may keep a minimum of four guppies and three mollies in your tank without any problems. This amount, however, may vary depending on the kind of mollies you keep in your 10-gallon tank with the guppies.

Mollies and Platies:

In a 10 gallon tank, you can keep 5-6 platies with mollies. Platies are a kind of tiny fish. When compared to mollies, they take up approximately half as much area. As a result, many platies can coexist with a single molly fish. 

Mollies and Tetras:

In a 10 gallon tank, you can keep 3–5 tetras with mollies. In a 10 gallon tank, three tetras and three mollies can live together at the same time. This number changes depending on the quantity of mollies and tetras in the tank.

You can keep a maximum of four glowlight tetras in a 10 gallon tank if you keep glowlight tetras.

What fish can live with mollies in a 10 gallon tank?

When picking a fish tank mate for your mollies, there are a few things to keep in mind. The size of the tank is a major consideration.

You must match the molly ratio with the fish tank buddy you will maintain in the aquarium. If you keep too many other fish in the tank with your mollies, it might cause some issues. 

Here are some names to remember if you’re looking for a fish tank companion for your mollies:

  • Guppy
  • Endlers
  • Platy
  • Swordtail
  • Neon Tetras
  • Zebra Danio
  • Monnows
  • Corydoras
  • Plecos
  • Angelfish

Final thoughts

2-3 mollies can be kept together in a 10-gallon tank. Mollies reach adulthood at a length of 3 to 5 inches. To swim freely in a tank, one molly requires at least 3 gallons of water. As a consequence, three mollies are able to live happily and conveniently in a 10-gallon tank.