How Many Guppies In A 5-Gallon Tank?

Guppies are notorious for being cute, adaptable, and not too demanding when it comes to tank conditions. That being said, there are some relevant factors that will weigh in quite heavily when it comes to accommodating this species.

Water quality, diet, tankmates, overall tank setup, lighting, temperature, all these make a massive difference in your guppy’s life.

But there’s one other factor that we should discuss here today, and that’s tank size. Guppies may be small, but they still require a minimum tank size.

Today, we will discuss guppies’ space requirements and whether you can fit them in very small, nano-sized tanks.

Is a 5-Gallon Tank Enough for Guppies?

Yes and no. Theoretically, a 5-gallon tank should be enough for 2-3 guppies, let’s say, purely in a survival sense. So, your guppies will survive in a 5-gallon environment, but they won’t thrive. There are several reasons for that:

  • Male territoriality – Guppies aren’t too territorial in nature usually, but that can change fast. A 5-gallon environment will bring out the worst in your guppy males since these are quite possessive about their space. Even if you only have 1 male and 2 females, for instance, the former will still feel threatened by the lack of space. Violence may soon become the norm, creating a tense environment that won’t benefit anyone.
  • The need for larger social groups – Guppies are social creatures, so they need each other’s company to feel comfortable, safe, and relaxed. You can keep a guppy pair in a 5-gallon tank since that should be enough space for them in theory. But keeping a guppy pair is kind of wrong in the first place. These fish need to live in larger groups, at least 6-8, since that’s the gold spot in terms of social cohesion. In this context, a 5-gallon tank won’t be enough.
  • The danger of overcrowding – Guppies will feel stressed when overcrowded, and a 5-gallon tank will provide the perfect circumstances for that. Even 3 guppies will feel overcrowded and claustrophobic in a 5-gallon environment. The danger with fish stress is that you may not notice it at first. It will become obvious after a while, at which point it may already be too late. Prolonged stress is known to lower the fish’s immune system, making the animal prone to parasites and bacteria.

So, I would say you can keep a pair of guppies in a 5-gallon tank, but not more. And I wouldn’t recommend that either. Your guppies will have poorer quality of life and shorter lifespans as a result. Make sure your guppies have at least 10 gallons of space available. Such an environment is perfect for a group of 5 guppies, along with the necessary decorations and plants.

Can One Guppy Live in a 5-Gallon Tank?

Yes, one guppy can live alone in a 5-gallon tank from a survival perspective. But that’s suboptimal, to say the least. The fish won’t feel comfortable in its environment, specifically due to its need for companionship.

Guppies can live alone, but I advise against it due to their well-developed social instincts. They need to live in compact groups since they love to interact with each other, exchanging playful mannerisms and occasional teasing. A guppy will survive on its own for a while, but it will experience significant drop in life quality and will have a shorter lifespan.

If you want a 1-fish tank, focus on other species like plecos, Oscars, betta, or paradise fish. Naturally, you want to invest in slightly larger tanks for them, so you also have that to ponder.

Can You Raise Guppy Fry in a 5-Gallon Tank?

Yes, you can raise guppy fry in a 5-gallon tank. However, it depends how many of them you have. And you’ll only be able to keep them in that environment for a while since these little guys grow fast.

Realistically, a 5-gallon would only fit only a few fry, and even these will quickly outgrow their environment. The problem with excessively small tank setups like this one is that they get dirty fast. The fry will also feel overcrowded, which will impact their growth rate, overall size, and general health.

So, I recommend having at least 10 gallons available even for fry. Guppies are known to be prolific breeders, so they will most likely give birth to dozens of fry at once. A larger tank will accommodate all of the fry, allowing them to grow fast and develop into healthy adults soon.

Can You Keep Endler’s Guppies in 5-Gallon Tank?

Whatever applies to regular guppies apply to the Endler’s variety. So, no, you shouldn’t keep Endler’s guppies in a 5-gallon tank for all the reasons we have already mentioned. Novice aquarists tend to apply different standards to Endler’s guppies compared to other guppy varieties based on size considerations.

Endler’s guppies are smaller than normal guppies, only reaching around 1.8 inches, compared to the former’s 2.5 inches. So, naturally, they require less space, right? Not quite. Endler’s guppies are just as active and space-demanding as normal-sized guppies, so they have similar space requirements.

A group of 5-6 Endler’s guppies needs at least 20 gallons of space; the same as any other guppy variations.

What Fish Can Live in a 5-Gallon Tank?

There are several fish species that can do reasonably well in a 5-gallon setup. These include:

  • White Cloud Minnow Mountain – This tiny fish can only grow up to 1.5 inches and can accommodate to life in a 5-gallon tank. You can have a group of 4 in such a setup. Just remember that 5 gallons is the minimum tank size requirement for this species.
  • Scarlet Badis – This semi-aggressive, carnivorous, and colorful fish will make for an amazing aquatic presence in your 5-gallon tank. They come from India and will accommodate to a smaller setup just fine. Just remember not to keep more than 1 male in the same environment. These tiny predators can get quite feisty towards each other. 1 male and 3 females should make for the golden Scarlet Badis group.
  • Dwarf Pea Puffer – This little submarine with bulging eyes and hummingbird-like fin movement is another great addition to a 5-gallon environment. The Dwarf Pea Puffer only grows up to 1 inch and doesn’t mind smaller environments. That being said, this species gives birth to a lot of explorers. The Dwarf Pea Puffer loves to roam its environment, so make sure you have a lot of plants, rocks, and decorations available to keep them busy. They’re also rather aggressive, so control the number of males to prevent outbursts of violence.
  • Celestial Pearl Danio – This is a nano-tank-specific species with amazing colors and a vibrant presence. The Pearl Danio remains between 0.5 to 1 inch in size and prefers planted tanks. You can easily accommodate several of them in a 5-gallon aquarium, so long as you provide them with the optimal living conditions. This is a peaceful, albeit rather territorial fish that will thrive in the proper setting. Provide the Pearl Danio with a variety of plants to boost its coloring and keep it calm, relaxed, and happy.

Naturally, there are multiple fish species that seem designed for small tanks. I would say prioritize those over fish like Betta, guppies, or any other species growing over 2 inches. As a general rule, if the fish is 1.5 inches or smaller, a 5-gallon tank may be enough. If it’s larger than 1.5 inches, consider upgrading the tank to at least 10 gallons.


You will see a lot of aquarium people recommending guppies as viable 5-gallon tank fish. I advise against that. I believe guppies require at least 10 gallons, preferably 20 for a respectable group. The more space they have, the healthier, happier, and more relaxed they will be.

A larger tank will decrease the likelihood of territorial violence and will keep your fish happier in the long run.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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