How Many Guppies in a 10 Gallon Tank [With Betta]?

How Many Guppies in a 10 Gallon Tank

The Guppy (Poecilia reticulata), popularly known as rainbow fish and million fish, is one of the most popular freshwater aquarium fish species. Again, it is also one of the most widely distributed tropical fish species in the world.

Native to northeast South America they come in various shades of grey and are in fact graded. Guppies have sexual dimorphism. The body color of wild-type females is grey, while the males have spots, stripes, or splashes, that could be any wide variety of colors.

Their vibrant body color, and ease to keep, make it highly popular especially for beginner aquarists.

In this article, we will discuss how many guppies are in a 10-gallon tank, the Guppy’s appearance and color grading, tank conditions, dietary needs, breeding, ideal tank mates, and much more…

Care Level:Easy
Color Form:Grey
Lifespan:2 Years
Size:Usually, males Guppies are 1.5–3.5 cm (0.6 to 1.4 in) long, while the females are 3–6 cm (1.2–2.4 in) long
Diet:Algal remains, diatoms, invertebrates, plant fragments, mineral particles, aquatic insect larvae, and other sources
Minimum Tank Size:5 Gallons
Tank Set-Up:Hard Water Aquarium, Heavily Planted
Compatibility:Other Snails and Shrimps
SpeciesP. reticulata
Guppies Stats and Facts

The first and foremost thing is to decide the size of your aquarium, next choose the fish breed you want to keep and the fish diet.

Plan the aquarium maintenance and its decoration. There are so many aspects you have to educate yourself on.

If you have consulted a pet expert, or a friend, or any biology book, or a fish trader, you’d probably know that guppies are nice pets. This species has been popular over the years from a complex, wide variety of fish.

Guppies are ideal for a beginner’s aquarium, too.

The reasons are:

  • Guppies are small in size and can be maintained very easily.
  • Guppies are colorful. They have reflective, glowing scales. You can pair red, green, orange, blue, or any other color combined together even in small fish bowls.
  • For beginners fish keepers, the bioload of Guppies are manageable.
  • They are active and peaceful.

If you are a beginner hobbyist, you just require a ten-gallon tank with a few guppies. At this point, the question pops up in our mind: How many guppies are in a ten-gallon tank exactly?

With what accuracy can you estimate the sufficient living and swimming space needed for a single guppy? What about their diet and tank mates? Their fry? Their maintenance? As a beginner, how many guppies should you have? How can you grow their population in a proper way?

Following are the solutions to some of the most important guppy-breeding doubts:

How Many Guppies in a 10 Gallon Tank?

Credit: With Ty/Youtube

We need 5-10 Guppies. Yes, Guppies can be kept in tanks as small as 10 gallons. However, the size you will need depends on the quantity you intend to keep in your aquarium. As a good rule of thumb, you can add 5-10 Guppies per gallon.

According to their age and pattern, Guppies vary slightly in its size. For an individual guppy, you should have a minimum of one gallon for every inch of your guppy.

At your local store, if you follow a size chart, you can simply estimate the volume of your aquarium. After that, you can decide how many guppies you can easily keep in your tank. If you are a beginner aquarist and have no idea, you can keep around 5 or 6 guppies.

From that moment, you will get some idea of how to maintain your guppies before you decide to keep more of them.

Guppies are easy to look after. You will face fewer problems while maintaining an aquarium with 5 or more grown guppies.

Here’s how you calculate the math to determine how much space guppies get in a 10-gallon aquarium.

How Do You Calculate How Many Guppies in a 10 Gallon Tank?

The practical fishkeeping rule is one gallon per one inch of fish. So, you would be able to add 10 inches worth of guppies in a 10-gallon aquarium. You can easily keep six male guppies in a fish tank of this size.

When the question comes to female guppies, you may keep four in your aquarium. If you are experienced one then you can push for three.

But for the fish keepers who are less experienced, we will recommend half of this amount. As an initial number, five guppies are sufficient for you.

Once you learn how to clean their tank, build their routine, and take care of their diet, you can add more fish to the guppie family.

But, that’s not everything. You can’t keep your aquarium abandoned, boring, and empty. The success mantra to keep your guppies fit and healthy is to give them the means of activity. There are so many things that you can place in your 10-gallon aquarium. The objects or things can include the following:

Toy Buildings

Props such as caves, monuments, castles, houses, etc. are some popular options for guppies. These are fun for your guppies and add to the beauty of your tank, too. Their shade is a source of comfort for pregnant guppies and young fry.

Guppy Tank Mates

In your aquarium, It’s better to keep various types of tank mates. Generally, the following are

assumed as the top tank mates for guppies:

  • Swordtails.
  • Catfish
  • Tetra fish
  • Molly fish.
  • Bottom feeders.
  • Angelfish
  • Gourami fish.

Usually, Guppies are peaceful fish. Therefore they can get along with various tank mate species. Ensure that the tank mates you consider not picking a fight with the guppies and have a very calm temperament.

The size of your guppies should also be compared with its fellow guppies. You may require to have not more than ten guppies in a ten-gallon fish tank if you keep tank mates. For a ten-gallon aquarium, a total number of 10 small fish is sufficient.

Aquarium Planters

A fish tank with coral-colored or lush green planters is a perfect treat to the eyes. These planters make the tank comfortable for guppies and are easy to maintain, particularly the young ones.

Shells and Rocks

Finally, an aquarium shouldn’t be kept empty at the bottom. You may fill the bottom of your aquarium with store-bought seashells, sand, or faux rocks.

After these factors are being considered, we can arrive at this point that a ten-gallon aquarium shouldn’t exceed 6 guppies. With all this added decor, guppies require sufficient space to eat, rest, and swim. The guppies may feel trapped if you fill up your aquarium too much. Before buying a tank, Pre-plan how many decoration pieces you require.

Does Gender Matter?

Normally the adult female guppies grow up to almost two inches in total length. By contrast, adult male guppies are relatively smaller and they grow up to 1½ inches in body length. If you’ve decided to keep them, usually it would be best to keep both males and females together in your tank.

What Will Happen If You Add Too Many Guppies In a 10 Gallon Tank?

Overpopulating an aquarium, no matter how big, is never a wise idea. In a ten-gallon tank, if you put more than 5 or 6 guppies and also tank mates with them here’s the consequences:

Unstable Water Parameters

Guppies always prefer balanced, healthy chemical compositions in the water. It’s the source of their life, and if it is contaminated, it might surely kill them. With an excessive amount of guppies, there is a chance of nitrite and ammonia spikes, which may cause the sickening of your guppies. In worse conditions, weaker and sick guppies might even die!

The Aquarium Will Get Dirty Often

Fish excretion remains in the bottom of your aquarium unless you clean it regularly. A tank with a few guppies and a sufficient amount of water can stay clear and clean for a longer period. The feces of your guppies will disintegrate very easily. On the other hand, an aquarium with a lot of guppies will get dirty very quickly and may even be a reason for diseases.

Killing and Aggression

If guppies aren’t provided sufficient room in the aquarium, these harmless fish can become very aggressive. This species may end up killing other guppies, fry, or tank mates.

Growth Issues and Deformities

Another common problem is Malnutrition that you may face in an overcrowded guppy tank. Guppies may have to struggle for their hiding places, requiring oxygen, and food. Guppies can also hinder their physical growth and cause some health issues if they don’t get enough aquarium volume to themselves.

Will the Aquarium Become Overcrowded Due to Breeding?

If you buy both male and female guppies together, they’ll surely mate every now and then. If a female guppy conceives babies each other month, it might be highly risky in a ten-gallon aquarium. A female Guppy can deliver anywhere between 10 to 120 babies.

At birth, each young fry is almost one-fourth of an inch. It takes about six months to fully grow. Guppies grow at an average of 0.3 inches each month to achieve the size of 2 inches. So, keep a separate aquarium for the fry or either avoid having both male and female guppies in the same aquarium.

As a beginner, If you want to have a family of guppies, then you have to wait for some time. At first, try keeping only a single-gender. You can bring in the other gender of Guppy to start a family once you completely understand how to keep guppies.

Make some arrangements for a fry tank simultaneously, it is because guppies mate quickly and frequently.

Do observe your pregnant guppies and keep them separately in a breeding tank when they are about to deliver.

A breeding tank will help to keep your pregnant guppy isolated from other adult guppies and tank mates, too. When the guppy fry comes out, place them in a separate box or aquarium. Since the fry is pretty small, you may keep more than ten fries in a single tank.

However, keeping ten or more fry in a single aquarium can easily become an issue later. Also, you cannot keep them in the same ten-gallon aquarium as other adult guppies because they might get killed and eaten.

If you have guppy fry, either sell them elsewhere or donate, buy a bigger tank or a separate tank.


Guppies are a very fascinating fish breed and no one can deny this fact. These species perfectly and quite easily encapsulate the beauty of marine life. Therefore, if you’re looking to brighten up your house with a beautiful aquarium, bringing guppies to your home is the way to go.

You can easily keep ten guppies inside your aquarium if you buy a ten-gallon tank. This article definitely helps you to figure out how to keep a 10-gallon aquarium healthy for your guppies without overcrowding them.


Dibyajyoti Bordoloi is the creator and author of, a third-generation experienced fish keeper and owner of a successful pet breeding farm. He is also a member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Kaziranga Nature Conservancy of Assam.

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