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How Many Ember Tetras Can You Have In a 10 Gallon Tank? Facts & FAQs

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By Lindsey Stanton

ember tetra

Ember tetras are some of the smallest aquarium fish you can get, usually topping out at about 0.8 inches in length. They are feisty, active swimmers, and their bright red coloration is definitely something to be admired.

These are small fish, but you still might be wondering how many ember tetras in a 10-gallon tank can fit comfortably? Each ember tetra needs roughly 1 to 1.2 gallons of space. Therefore, for a school of 8 ember tetras, the ideal tank size is 10 gallons.

Let’s take a closer look at ember tetra tank size, tank requirements, and more.

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Minimum Tank Size for Ember Tetras

The smallest tank size for a school of ember tetras is 10 gallons. Now, you might be wondering why they need so much space, after all, one ember tetra is under an inch in length.

While it is true that a single ember tetra needs somewhere around a gallon of tank space, they are strictly schooling fish and should never be kept alone. You need to keep multiples together, which is why a decent size tank is necessary.

How Many Ember Tetras are in a School?

Ember tetras find safety in numbers. They are schooling fish and should be kept in groups of no less than eight.

Ember Tetra Housing Requirements

The tank size for ember tetras is not the only thing that you need to consider. Before you go out and buy a school of ember tetras, there are a few important housing requirements which you need to keep in mind.

Water Temperature

Image Credit: Matteo Fusco, Unsplash

Ember tetras are quite hardy and can survive within a wide temperature range. They require the water to be between 68 and 82 degrees Fahrenheit. This means that, depending on where you live, you may not need an aquarium heater, at least not to keep it at around 68 or 69 degrees.

However, the ideal temperature for ember tetras is somewhere in the mid 70’s, and to keep this temperature steady, you may want to invest in an aquarium heater.

Water Hardness

Ember tetras are also not too demanding in terms of water hardness. As long as you keep the hardness level below 18 dGH, they will be fine. Remember that this means that the water needs to be soft or moderately soft.

However, these fish do not do well in excessively hard water, so this does need to be avoided. You may require some water conditioner to keep the water soft enough to support a school of healthy ember tetras.

Water pH

Ember tetras require the water to have a pH level between 5.5 and 7.0, with 5.5 being fairly acidic and 7.0 being neutral. That said, these fish cannot handle alkaline water, with the ideal pH level being somewhere around 6.2.

To keep the water this acidic, you may require water treatment liquids or decorations like driftwood that can make the water more acidic. Either way, it is recommended that you get an aquarium pH meter so you can accurately measure the acidity of the water.

Filtration & Aeration

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Image Credit: Cock-Robin Pixabay

Ember tetras are usually found in fairly still waters without much of a current, as well as fairly clean water. Therefore, you will need a filter that has the ability to keep the water clean without producing a heavy current. Something like a small hang-on-back trickle or waterfall filter should do fine, something that allows you to adjust the flow rate.

Moreover, for something like a 10-gallon ember tetra tank, a filter that can process roughly 30 gallons of water per hour is ideal, and it definitely needs to engage in all three major forms of water filtration, including mechanical, biological, and chemical filtration.

If you have a good filter and a few good plants, you should not need to add any oxygenation or aeration to the mix. The filter should do this for you.


Aquarium light_TIPAKORN MAKORNSEN_Shutterstock
Image Credit: TIPAKORN MAKORNSEN, Shutterstock

In terms of lighting, a normal and moderately bright aquarium light will do just fine. As long as it can mimic natural sunlight and provide some light to the tank, you should not have any problems. It does not need to be anything special, although extremely dim lights are not recommended, just something moderate in brightness.


Neon tetras, due to the fact that they usually stick to the middle of the water column, do not have special substrate requirements. You may use either sand or gravel. We would recommend going with a dark substrate, even black because this will make the red on the ember tetras really stand out.

Something you will want to consider however when choosing between sand and gravel is what kind of plants you want in the tank.


When it comes to plants, be somewhat sparing with them, as ember tetras are fast and agile swimmers, and they do like to have a good bit of open water to swim. Therefore, you can add some small plants to the mix, ones that don’t grow too wide or too tall.

Most people choose to go with plants that can be attached to driftwood and rocks, as well as some free-floating plants, too. People who keep ember tetras often go for something like hornwort.

Rocks & Deco

pond rocks
Image Credit: andy0man, Shutterstock

The same thing can be said for rocks, caves, and driftwood as for plants. A cave and a piece of hollow driftwood should do fine. Remember that you don’t want to crowd the tank. Much of the space should be left open for swimming.

Tank Mates

Ember tetras should not be kept with much larger or aggressive fish that are likely to harass them. Anything peaceful or just slightly larger will do fine.

Some good ember tetra tank mates include other tetras, danios, small Corydoras, and other such fish. Betta fish, goldfish, cichlids, and any other larger and aggressive fish needs to be avoided.



Can Ember Tetras Live with Guppies?

Yes, guppies and ember tetras should get along just fine. They are fairly similar in size and both are peaceful.

Can Ember Tetras Live with Bettas?

No, absolutely not. Betta fish will most likely attack and harass your ember tetras.

How Many Ember Tetras can I Put in a 5 Gallon Tank?

Technically speaking, you could keep about four ember tetras in a 5-gallon tank. However, these fish should not be kept in schools smaller than eight fish. Therefore, keeping four in a 5-gallon tank is not recommended.

Are Ember Tetras Hardy?

Yes, ember tetras are fairly hardy, and this makes them perfect for community tanks with varying water conditions.

Image Credit: Ivabalk, Pixabay

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Ember tetras may be small, but they are fast swimmers, they are agile, and super brightly colored too. These are easy to care for animals that make for great beginner fish.

Featured Image Credit: InsectWorld, Shutterstock

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