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How Many Neon Tetras in a 10-Gallon Tank? Our Vet Answers

Dr. Luqman Javed, DVM (Vet)

By Dr. Luqman Javed, DVM (Vet)

blue neon tetra fish inside beautiful freshwater aquascape with live aquarium plants

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Dr. Luqman Javed

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It can be pretty difficult to judge how many fish can fit in a certain size aquarium. After all, each type of fish usually has different spatial requirements. This is only made harder when you want to set up a community tank with various fish species within it. For instance, if you want to get a 10-gallon tank and have Neon Tetras, you will need to know how many of them can fit.

After all, these little guys are schooling fish, so you cannot keep them alone, but if you have a limited 10-gallon tank, you also cannot cram too many of them into that small space. You could safely house a maximum of around eight to 10 Neon Tetras in a standard 10-gallon tank without issue, assuming that there are no other fish in the tank and you are on top of your aquarium maintenance tasks.

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Neon Tetras & 10-Gallon Tank Housing

Figuring out how many fish can be housed in an aquarium is a tricky prospect. Each fish species has unique characteristics. A popular “rule” is having 1 gallon per inch of fish in your aquarium. However, this “rule” is exceptionally misleading and doesn’t work in a spatial sense. Here are a few reasons that you should not follow this misconception when it comes to stocking your tank.

Fish Are Not One Dimensional

When it comes to calculating how many fish can fit in a certain area, you are better off going with a liberal estimate in terms of fish size, rather than assuming that you need 1 gallon per inch of fish. Fundamentally, fish are not one dimensional. They have varying degrees of height and girth, which should be factored into an owner’s decision when it comes to housing them. For example, if a tank is long but not wide enough, a particularly long fish will struggle to turn in the aquarium. Likewise, some fish are taller than they are long, so the faulty “rule” will physically not work for them.

Tropical fish swimming in lighted aquarium or fish tank
Image Credit: Sergio Bertino, Shutterstock

Fish Have Physiological Needs

Fish have different physiological needs in terms of the space that they require. Territorial fish usually need more space than schooling fish. The latter appreciate each other’s company and tend to stick close together.

Likewise, some fish have different swimming preferences. For example, Discus fish prefer to swim along the vertical column of water, so their space needs to factor in enough height for them. All this must be accounted for prior to stocking your aquarium.

Fish Have Different Bioloads

Different species of fish produce different amounts of waste, also known as their bioload. A fish with a high bioload is safer in a larger aquarium than a fish of the same size that produces a low bioload. For example, a young 1.5-inch Goldfish will produce far more waste than an adult 1.5-inch Neon Tetra.

How Many Neon Tetras in a 10-Gallon Aquarium?

Neon Tetras are schooling fish and have a generally low bioload. They aren’t overly active and don’t physically grow large enough to outgrow a standard 10-gallon aquarium (20 inches length x 10 inches depth x 12 inches height). For Neon Tetras specifically, you can follow a rule of 1 fish (not inch) per gallon for any aquarium under 30 gallons in size.

A fully cycled and appropriately heated and filtered 10-gallon aquarium, which is subject to weekly partial water changes of around 20–25%, can safely house eight to 10 Neon Tetras, assuming that there are no other fish in the aquarium. 

Neon tetra in aquarium plant in the background
Image Credit: Lapis2380, Shutterstock

Play It Safe

It is always better to get a bigger tank than 10 gallons if money and space allow. It’s generally always good to give fish extra space, and this also allows for more decorations/plants (which also take up water space).

How Many Neon Tetras in a 10-Gallon Tank With Betta Fish?

Neon Tetras are peaceful schooling fish. Their disposition makes them popular choices for a community setup. Of course, lots of people want to have more than one type of fish in a tank.

One really popular fish is the Betta fish (Betta splendens). Betta fish do tend to be a bit territorial, but they usually only attack fish that they perceive to be a threat to their territory. That said, territorial aggression is often bred into Bettas, and there’s no guarantee that Neon Tetras can be housed with Bettas—this is a gamble that may or may not work. In other words, some Bettas can be successfully housed with Neon Tetras, whereas others cannot.

betta fish
Credit: panpilai paipa, Shutterstock

If you are willing to take the risk and have backup aquariums in case this setup does not work out, an acceptable stock for a 10-gallon aquarium is as follows:

  • 6 Neon Tetras (ideally in the aquarium before the Betta is introduced)
  • 1 Betta (Betta splendens)

Please remember that there is no guarantee that this setup will work. If you notice your Betta acting aggressively toward your Neon Tetras, you will have to separate them. Also, keep in mind that the nutritional requirements of these two species are somewhat different.

How Many Neon Tetras and Guppies in a 10-Gallon Tank?

Another nice-looking, peaceful, and mild-tempered tank mate to go with for Neon Tetra fish is the Guppy (Poecilia reticulata). Guppies are generally a little larger than Neon Tetras but differ in size based on their sex. Males can grow to 1.4 inches long (1 inch being the average), while females are known to get up to 2.4 inches long (2 inches being the average).

Multi color Poecilia reticulata,on black background with clipping path
Image Credit: panpilai paipa, Shutterstock

Despite their size, Guppies produce a very high bioload and need appropriate levels of filtration to thrive. If you plan to house Guppies with your Neon Tetras, consider the following as your upper limit:

  • 6 Neon Tetras (ideally in the aquarium before the Guppies are introduced)
  • 2 Guppies

Please note that Guppies are best housed in a ratio of at least two females per male, with even more females preferred per male whenever possible. As a 10-gallon tank can only comfortably house two Guppies with a school of Neon Tetras, they should both be the same sex. Females purchased from a mixed group of Guppies may already be pregnant when brought home, which is something that you will need to factor in.

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FAQ

How Many Neon Tetras in a School?

The absolute minimum number of Neon Tetras in a school is six. However, they seem to appreciate more numbers and put on better schooling displays when housed in groups of 15–20 or more.

cardinal tetra
Image Credit: Pixabay

How Many Neon Tetras Should I Get?

The correct answer to this question is, “as many as your tank can comfortably fit, but never fewer than six.” Large tanks can house large schools. For example, if you’re keen on a species-only tank, a 55-gallon aquarium could house a school of 55–60 Neon Tetras!

How Many Neon Tetras Can I Put in a 2.5-Gallon Tank?

The answer is one, but it’s not recommended to house them in a small tank or alone. However, this might be necessary when you wish to medicate a single injured or ill fish in an attempt to help them recover before rejoining their school.

Do Neon Tetras Need an Air Pump?

No, in general, Neon Tetras do not require an air pump. Usually, if you have not overloaded the tank with too many fish, and all your fish are in acceptable water parameters (not too warm or cold) with adequate filtration, there should be more than enough dissolved oxygen in the water to keep your fish healthy.

The addition of live aquarium plants known for producing large amounts of oxygen can also help aerate your aquarium.

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Conclusion

Neon Tetras are small-sized peaceful fish that make fascinating pets because of their relatively small size, stunning coloration, and schooling displays. Nonetheless, they should be housed in an appropriately sized aquarium. A 10-gallon aquarium can house a school of eight to 10 Neon Tetras if set up properly.

The number of Neon Tetras that you can keep in such an aquarium will change if you decide to go for a community setup with other fish, such as the popular Betta. However, it is important to keep in mind that since Neon Tetras are schooling fish, you cannot reduce their numbers excessively; at least six individuals are recommended as a minimum.

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Featured Image Credit: Alex Unders, Shutterstock

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