How Many Guppies In A 5 Gallon Tank? (2024 Complete Guide)

Guppies swimming in an aquarium
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Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: July 7, 2024
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Most of us are familiar with the typical setup in many pet stores: numerous fish packed into a small glass tank, devoid of any decorations, substrate, or plants.

Surely this can’t be the ideal situation, right? Even when trying to maintain smaller tanks such as a 5 gallon aquarium, we need to ensure that there is enough space for all of our guppies to feel safe and comfortable.

This can prove to be quite the challenge when initially setting up any size tank, which is why we’ve made this guide for keeping guppies in fish tanks.

Today we’ll look at answering the question “How many guppies in a 5 gallon tank?” in addition to some other general guppy questions and concerns. Read on for more!

Article Summary

  • The number of guppies you can keep in a 5-gallon tank depends on factors like guppy size, diet, and territory requirements.
  • A general recommendation is 2-4 guppies in a 5-gallon tank, with 2-3 being suitable for beginners.
  • In a 5-gallon tank, having more than three male guppies can lead to aggression and injuries; for female guppies, the same space recommendations apply, with 2-4 being suitable for a 5-gallon tank.

How Many Fish Can Live In A 5-Gallon Tank?

The answer to this question may seem simple but has a lot of variation.

For how many fish, today we’ll be considering a guppy’s size, diet, and territory requirements which can vary between fish and species leading to different needs in the same aquarium. But in general, it’s always best to try to mimic their natural habitat and provide them with the right tank size.

Guppies and Aquatic Plants
Guppies and Aquatic Plants

As a general rule for guppies, I would recommend 2-3 guppies in a 5 gallon aquarium for beginning aquarium hobbyists. Even for experienced fish keepers, I wouldn’t recommend more than four in such small aquariums.

For instance, since certain tropical fish such as betta fish require quite a bit of room to themselves in order to feel comfortable. These fish take a minimum of 5 gallons to themselves, meaning that bettas may not be the best combination with guppies, even if they tend to be good neighbors.

How Many Guppies Should I Get?

The answer to this is really up to you! As long as you follow the proper size guidelines for multiple guppies in the same fish tank, you can potentially have as many as you like.

However, if you’re aiming to have a small tank in the 5 gallon range, you’ll need to set a limit at between two guppies and four. You’ll need a larger tank size if you want to keep more. Having more than four guppies can also make it difficult to maintain water parameters.


Any more guppies in a 5 gallon tank and you may be facing issues with crowding. This, coupled with too warm water can create problems with your aquarium water, as the guppies overwhelm the tank’s ability to complete the nitrogen cycle and remove ammonia and maintain water parameters.


The most common reason fish get sick is overcrowding!

One Inch Per Gallon: Rule or Myth?

Brightly Colored Guppiees
Brightly Colored Guppies

There’s a commonly held belief (and misconception) in the aquarium world that for most smaller fish breeds you can adjust your number of fish to the amount of inches of fish you have.

The general idea is that for each inch of fish, you should have an additional one gallon tank size.

This is wrong!

While this may sound like a convenient way to size your fish tank, it comes with some caveats that make less sense in the long run.


Considering that for a single guppy fish the minimum tank size is 5 gallons and that a typical guppy fish grows to around 1-2 inches in length, you’d be shorting your poor fish by at least 3 gallons of precious space!


While guppies can technically live in small fish tanks, having extra room means a less stressed out fish in the long run. Think about being crammed into a small box all day without enough room and you’ll get the rough idea!

A 1-2 gallon tank is a very small tank indeed, and without proper chemical filtration and aquarium filter maintenance, it will not be ideal in keeping guppy fish healthy in the long run.

Additionally, guppies grow (albeit slowly) over their life span and will need more than just the 1-2 gallon fish tank if they reach a larger size than you initially anticipate.


The best way to size is to always start with the minimum requirement for your fish tank and add more than you need.

How Many Guppies In A 5 Gallon Tank?

In a 5 gallon fish tank, I would recommend no more than four guppies. Anywhere between one and three guppies can be great in one fish tank, with more than that potentially leading to health problems in the long run.

When it comes to how many guppies you can have in a five gallon tank, it’s better to opt on the side of allowing more space for your fish to swim freely rather than packing them in together.

Adding in live plants, rather than more guppies can be a great alternative.

Check out the video below to see what a 5 gallon tank with guppies would look like.

How Many Male Guppies In A 5 Gallon Tank?

Can you keep only males? Considering that guppies are schooling fish, it’s not a bad idea to have more than one male guppy fish in the same fish tank.

When keeping male guppies, keep in mind that they will potentially compete for space, meaning that it can be important to factor in plenty of hiding places and break the line of sight between your fish.


In a small, 5 gallon fish tank, big guppies can mean even less room for others. Factor this in when thinking about how many guppies you’d like and whether you may need fewer guppies in such a small tank.

While male guppies are not innately territorial, having only male guppies in a fish tank can still lead to issues with competition for space as male guppies are quite active fish.

Dangers of Limited Space

In a 5 gallon tank, having more than three male guppies or so will lead to the incidences of harassment and aggression between your fish as they fight more for space than to show dominance.

Even a small, one inch fish can cause severe damage to another if an injury becomes infected. This means that guppies die due to poor planning on the part of the aquarist, something that could have been easily avoided.

How Many Female Guppies In A 5 Gallon Tank?

Can you keep only females? In general, the same rules apply for females as males. If trying to have more than one fish. For a female guppy tank I recommend that you stick to two female guppies up to four female guppies.

Again this is more for issues related to space than to competition. Having more female guppies than this recommendation is likely to lead to issues with water chemistry and poor aquarium water quality as waste accumulates and overwhelms your filters. Having the right filter for your 5 gallon tank will help keep guppies healthy and parameters stable.

Can I Keep Just One Guppy Fish in a 5-Gallon Tank?

Colorful Male Guppy
Colorful Male Guppy

Yes, you can absolutely keep one guppy fish by itself in a 5 gallon tank! Just because these freshwater fish school naturally in the wild does not mean that they necessarily socialize or will get lonely.


People often like to project their own feelings onto their guppies, but think of it more like a shared apartment space. You’d much rather have a whole place to yourself than share with a bunch of potential strangers, right? So would your guppy!

Having a single fish in a 5 gallon tank rather than trying to cram too many guppies in the same space will lead to a single happy fish, rather than multiple stressed out ones.

Your fish tank will also have more room for additional live plants and decorations, which will be sure to please your fish.

Keeping Males and Females in the Same Tank

Male and Female Guppy
(1) Male and Female Guppies

You can absolutely keep male and female guppies in the same tank. Keep in mind that even when trying to breed guppies, the same idea of not overcrowding holds.

Adding in too many fish at one time can lead to guppies dying from disease or ammonia poisoning as conditions in the fish tank decline.


Wondering how to tell when one of your guppies is pregnant? You’ll typically see the fish’s sides expand as she fills with eggs, a telltale sign that she’s ready to lay.

For an ideal male to female ratio, consider no more than one male to every three females in the same fish tank.

The reason for this is that during their breeding cycle, males will attempt to harass the females in the tank, chasing them and attempting to breed.

These small fish can potentially cause damage to others, especially its own kind. Spreading this out between multiple females lessens the chance of any damaging encounters.

Guppy Breeding


Why breed guppies? Guppies are one of the best fish to learn about breeding with! Keep in mind that guppies reproduce rapidly, and can quickly make more guppy fry than you may be prepared for!

A single female can produce up to 50 guppies in one brood…

A single female can produce up to 50 guppies in one brood, and reproduces every 30 days in ideal conditions. Young guppies grow to a mature, reproductive age in as few as 2-3 months. In a 5 gallon tank, it can be easy to see why this may quickly spiral out of control!


Throughout today’s article we’ve looked at the proper amount of guppies to add to a 5 gallon aquarium.

In general, I recommend no more than four guppies in order to ensure that each has enough room to call its own. If you’d like to have other fish or many guppies, I’d recommend that you look at potentially purchasing a bigger tank.

Feel Free To Share!

As always I hope that you’ve found today’s post on how many guppies in a 5 gallon tank to be informative and useful.

Feel free to share it with anyone in the aquarium hobby or other fish fanatics that you may know and I wish you the best of luck on your continued aquarium adventures.

(1) Marrabbio2, CC BY-SA 3.0, via Wikimedia Commons

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