How Many Guppies in a 10 Gallon Tank?

If you’re new to the fish keeping hobby, you’re feeling either of these two: 

  1. Excitement.  
  1. Confusion. 

Or maybe, both. 

You have to decide on tank size. Choose the fish breed and fish diet. Plan the tank decoration and maintenance. In a nutshell, there’s a lot you need to educate yourself on. If you’ve consulted a fish trader, a friend, or any biology book, you’d know that guppies make nice pets. From a wide, complex variety of fish, the guppies have been popular over the years. 

These are ideal for a beginner’s fish tank, too. The reasons are pretty obvious, too: 

  • Guppies are colorful and have glowing, reflective scales. You can pair orange, green, blue, red, or any other color together, even in small aquariums. 
  • Guppies are small in size. 
  • Their bio-load is manageable for beginners. 
  • They are peaceful and active. 

So that’s settled. As a beginner hobbyist, you need a ten-gallon tank with some guppies. Hence the question pops up: How many guppies should be in a ten-gallon tank? 

How exactly can you figure out the sufficient swimming and living space required for one Guppy?

If your Guppy is swimming upside down, however, It can be a sign of something else. Find out what it means here!? What about their fry? Their diet? Their maintenance? Other tank mates? How many guppies should you have when you start? How can you grow their population? Here are the answers to some of the most important guppy-breeding questions: 

How Many Guppies in a 10 Gallon Tank? 

Guppies vary slightly in size according to their type and age. For a single guppy, you need at least one gallon for every inch your Guppy is. By following a size chart at your local store, you can estimate the volume of your tank. Then, you should determine how many guppies you can easily keep in there.  With this in mind.

You can add 5-6 guppies to a 10 gallon tank as guppies generally grow to about 1.5″ – 2″ in size. With that being said, if you’re new to fishkeeping then you should consider keeping 3-4 guppies to reduce the chance of something going wrong.

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

To calculate how many guppies for your tank, the general rule of thumb is one gallon per one inch of fish. Therefore, in a 10-gallon fish tank, you can add the equivalent of 10 inches worth of guppy.

More precisely, you can keep six males in an aquarium of this size. When it comes to females, you may keep four, but experienced people can push for three.  

But for those who aren’t experienced fish keepers, we would suggest half of this amount. Five guppies as an initial number are enough for you. Once you learn to take care of their diet, clean their tank, and build their routine, you can add more to the family. 

However, that’s not all. You can’t keep a fish tank empty and boring. The key to keeping guppies healthy is to provide the means of activity. There are more objects that you should place in your 10-gallon tank. This can include the following: 

Toy Buildings 

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

Tank Mates 

Yup, it’s better to keep a variety of tank mates in your guppy tank, too. Usually, the following are considered the best tank mates for guppies: 

Guppies are normally peaceful, so they can get along with a number of tank mate species. Just be sure that the mates you consider have a calm temperament and do not pick a fight with the guppies. 

They should also be comparable in size with their fellow guppies. If you keep tank mates, you may need to have less than ten guppies in a ten-gallon tank. Overall, a total of a maximum of 10 small fish is enough for a ten-gallon tank. 

Tank Planters 

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

Rocks and Shells 

Lastly, a tank isn’t kept empty at the bottom. You may fill it with stores bought faux rocks, sand, or seashells.  

Considering all these factors, we can say that a ten-gallon tank shouldn’t contain more than 6 guppies. With all this added decor, guppies need ample space to swim, eat, and rest. If you fill up your tank too much, your Guppy may feel trapped. Pre-plan how many decoration pieces you need while purchasing the tank.  

Does The Gender Of The Guppies Matter? 

Female adult guppies normally grow up to almost 2 inches in length. By contrast, male adult guppies are smaller and grow up to 1½ inches in length. However, if you’re going to keep them, normally, it’s best to keep males and females together. (Here’s a helpful article on keeping male and female guppies together.)

What Will Happen If You Add Too Many Guppies? 

Overpopulating a fish tank, no matter how large, is never a good idea. If you put more than 5-6 guppies and tank mates in one ten-gallon tank, here’s what can go wrong: 

Unstable Water Parameters 

Guppies need healthy, balanced chemical composition in their water. It’s their source of life, and if contaminated, it can kill them. With too many guppies, there is a chance of ammonia and nitrite spikes, which can sicken the guppies. In worse cases, weaker guppies may even die! 

The Tank Will Get Dirty Often 

Fish excretion remains in the tank unless you clean it. A tank with sufficient water and a smaller number of guppies can stay clean and clear for longer. Their feces will disintegrate easily. On the opposite side, a tank with too many guppies will get dirty too quickly and may even be a cause of diseases. 

Aggression and Killing 

If guppies aren’t given enough space in the water, these harmless creatures can become aggressive. They may end up killing other tank mates, guppies, or fry. 

(Find out more about aggression in guppies.)

Deformities and Growth Issues 

Malnutrition is another common problem that you may face in an overcrowded guppy aquarium. Guppies may have to struggle for food, sufficient oxygen, and hiding places. If guppies don’t get a sufficient amount of tank volume to themselves, it can also hinder their growth and cause health issues. 

(Another common reason this can happen is when they aren’t bred properly. Here’s a guide on how you can selectively breed your own guppies.)

Will the Tank Become Overcrowded Due to Breeding? 

If you purchase a mix of male and female guppies, they’ll most definitely mate every now and then. If a guppy conceives babies every other month, that can be too risky in a ten-gallon tank. Guppies can deliver anywhere between 10 and 120 guppies. 

Each young fry is about one-fourth of an inch at birth and takes six months to fully mature. To reach the size of two inches, guppies grow at an average of 0.3 inches every month. So, either avoid having male and female guppies in the same tank or keep a separate tank for the fry. 

(Want to know more about how long it takes guppies to grow?)

If you want to grow a family of guppies as a beginner, you should wait for some time. Try keeping only one gender at first. Once you understand how to keep guppies, bring in the other gender to start a family. 

Simultaneously, make arrangements for a fry tank because guppies mate frequently and quickly. Keep an eye on your pregnant guppies and place them separately in a breeding box when they’re about to deliver. 

A breeding box will keep the pregnant Guppy isolated from other adult guppies, too. When the fry comes out, place them in a separate tank. When the fry is small, you may keep more than ten in a tank since they are pretty small. 

But keeping more than ten fries in a tank can easily become a problem later. You also cannot place them in the same ten-gallon tank as other guppies because they might get eaten. If you have guppy fry, either donate or sell them elsewhere, buy a separate tank or a bigger tank. 


Here are some frequently asked questions that people have about how many guppies they can keep in a 10 gallon tank!

How Many Guppies Should Be Kept Together Generally?

You should maintain at least three guppies in a an aquarium that is a minimum of 5 gallon in size. Simply increase the tank size according to the number of guppies you intend to keep more.

How Often Do Guppies Breed?

Female guppies can produce offspring monthly (once every 30 days). If the conditions are favourable and the tank contains male and female guppies.

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There’s no doubt about the fact that guppies are a fascinating fish breed. These fish breed quite easily and perfectly encapsulate the beauty of marine life. So, if you’re looking to brighten up your house with a nice aquarium, getting guppies is the way to go.   

If you buy a ten-gallon tank, you can easily house ten guppies inside. This guide helps you to figure out how to keep your 10-gallon aquarium healthy for guppies without overcrowding them.