Tetras Lifespan: How Long Can Tetra Fish Live Without A Filter

tetra fish

Tetras are considered to be active schooling fish that function well in a peaceful and serene aquarium. It is best to stock six or more tetra fish of the same species in an aquarium but mind you, the size of the aquarium should be considered first so as to determine the suitable stocking density for the aquarium.

Filters are one of the critical components of aquariums be it freshwater or saltwater aquarium. Filters are important because they remove physical waste products from the aquarium. Filtration also increases the oxygen in the tank by causing water movement.

Tetra fish can live for 48 hours without a filter given that the bioload in the aquarium is minimal. But if you want them to live for a longer period without a filter, you need to be performing a 25% daily water change to increase the oxygen level in the aquarium and reduce the pollution. Having a heater can be helpful in such an aquarium to provide optimum living conditions for the fish. 

The primary purpose of the filter in the aquarium is to remove fish excrement, excess food, solid and free-floating particles, decaying organic matter, and harmful chemical substances from the aquarium water.

Tetra Fish Aquarium Care

Tetra fish family contain little sparkling and beautiful fish and they are easy to incorporate into community aquarium or any other kind of fish tank setup. One good thing about Tetra fish, they can be kept and cared for by both beginners and expert aquarists with ease.

Care LevelCan be challenging
Color FormVaried among species
SizeUp to 2″
DietOmnivore (will eat prepared food)
Temperature69-830F (22-280C)
Minimum Tank Size15 Gallons
Tank Set-UpTropical freshwater with open swimming space
AvailabilityVery Common


  • Tetras should be kept in a minimum of 15 gallons (57 litres) cycled tank. As a beginner aquarist, you should strongly consider starting with a larger tank size because it’s better for larger shoals and it also gives a wide error margin when maintaining the aquarium.
  • High temperature can make tetra fish hyperactive and increase their metabolic rate leading to stress. Likewise, a lower temperature will affect their immune system. So, their temperature should be optimum at all times.
  • In the wild, tetras live in soft to very soft water. Therefore, putting them in hard water will affect their internal system.


With that said, A heater, mild illumination, some plants, a small air pump, and a sponge filter should be enough for successfully keeping tetra fish.

When lighting a tetra aquarium, a dark background is preferable because it will help them settle in and reduce their stress level.

Tetra fish don’t function well when lights come from the bottom of the tank, so you should use dark colour instead.

This will help their color to pop out and at the same time will prevent them from going pale when attempting to hide.

Neon Tetra and Cardinal Tetra fish

neon and cardinal tetra

Neon Tetras are environment-friendly tetra fish and have been in the aquarium hubby fish for a longer time than cardinal Tetras. A simple sponge filter is enough to take care of the nitrification process in their aquarium.

Neon tetras are active fish that function well in school. They prefer to be kept in groups of six or more tank mates. In the wild, they are mostly found in slow-running water, and this can also be done by keeping them to mimic their natural environment.

Cardinal tetras are more expensive in comparison to neon tetra, but many aquarists prefer cardinal tetra because of their brighter coloration.

Cardinal tetras can be kept together with neon tetra in the aquarium because they are both peaceful fish and they originate from the same habitat.

Housing Requirements for Tetras

1. Decoration

Since tetra fish originate from the Amazon River Basin, therefore the most natural plant décor are plants that also originate from the Amazon River, e.g. Amazon Sword Plant. But you can also use fake plants and décor as they work perfectly fine.

2. Substrate

Large gravel that won’t fit the mouth of the fish should be chosen to prevent choking. Like I said earlier, a dark coloured substrate is recommended for tetra fish.

3. Equipment

You need to incorporate a heater and a filter into their aquarium to provide a suitable living condition for both the fish and beneficial bacteria.

Tetra Fish Feeding

What Do Tetras Eat?

Most Tetra fish are omnivorous, meaning that they can eat both animal and plant food sources. They love to eat small worms and insects. In the wild, they eat algae, small invertebrates, and crustaceans.

Feeding Tetra fish.

It would be best if you were feeding tetra fish with a variety of foods to ensure balance and adequate amounts of nutrients.

It would help if you fed newly acquired tetras with live foods such as brine shrimp, Daphnia monia, fruit flies, and ground worms.

For best result, you should rotate their diet daily and feed them only what they can eat within two minutes. This will ensure that they finish all the food you fed them. This is because excess food will settle at the bottom of the aquarium, thereby increasing the biomass and if there is no functioning filter in the tank, it will lead to illness and infection among the fish.

Tetra Fish Tank Mates

It would help if you only kept tetra fish in a tank with peaceful, small, and herbivorous fish. I won’t suggest Guppies, Molly, and halfbeaks because they are hard water fish. I won’t suggest Angelfish either because they can easily cannibalize on tetra fish once fully grown.

Here is my suggestion of tank makes for tetra fish that have little to no chance of failing, provided they are equally taken care of.

  1. Sparkling Gourami (Pygmy Gourami)

Sparkling Gourami

This is my number one recommended fish because they are one of my favorite freshwater fishes for aquariums because Sparkling gourami care is very easy and can be taken care of by beginner hobbyists and they are also beautiful.

Like Tetra fish, sparkling gourami is also small freshwater fish and doesn’t require large tanks to survive. They are also an omnivore, and they mostly eat zooplankton and insects.

Sparkling gourami is a gentle and peaceful fish. They are active fish and enjoyable to watch.

Sparkling gourami Descriptions

Water Temperature750F to 810F (240C to 270C)
Water Hardness5 – 10 dKH
pH6 – 8
Size1.5” (4cm)
  1. Bolivian rams

 Bolivian rams

Bolivian Rams are a beautiful addition to tetra fish in a tank. They are very peaceful fish and can easily get along with other fish in a tank without issues.

Bolivian Ram is easy to care for once you stick to their preferred water parameters. The best thing is to mimic the water parameters of their natural habitat.

A standard filtration system will work perfectly for them. You just need to make sure that the filter is powerful enough to treat the water efficiently.

Bolivian Ram Descriptions

Water Temperature700F to 800F (210C to 270C)
Water Hardness1 – 10 dKH
pH6 – 7.5
Size3” (8cm)
  1. Tetras and their species

Tetras and their species

Most tetra fish are peaceful and can get along well with one another of similar-sized but with some exceptions. For example, Serpae tetras have a tendency to bite especially when they are kept in small numbers.

Other species like Buenos Aires tetras can get quite large, active, and intimidating to smaller and timid fish. But in general, they are all good tank mates.

  1. Corydoras Catfish

Corydoras Catfish

Corydoras catfish are eye-catching catfish with their tiny whiskers. They are shoaling species and rarely kept appropriately by aquarists. They are happy in groups of six or more.

Corydoras are peaceful and generally keep to themselves by not making any trouble in their habitat.

Corydoras are small fish which makes them suitable to be kept with tetra fish. They also have a pretty long lifespan.

Corydoras Catfish Descriptions

Water Temperature700F to 800F (210C to 270C)
Water Hardness2 – 10 dKH
pH5 – 7
Size3.5” (9cm)
  1. Harlequins Rasboras

Harlequins Rasboras

Harlequins Rasboras don’t cause many problems, as they are known to be easy to keep. They are not aggressive and tend to stay away from taller or more energetic fish.

Harlequins are named after black marks reminiscent of a harlequin costume. These signs are clearly distinguished by the subtle shades of silver, orange and blue that are normally found on its main body.

Harlequins Rasboras Descriptions

Water Temperature720F to 820F (220C to 280C)
Water Hardness1 – 10 dKH
pH5 – 7.5
Size2” (5cm)

Putting It All Together

Now that you are aware of how long it can take tetra fish to live without a filter, now is the right time to get your tetra fish aquarium filter if you want them to be performing at their best and to avoid unnecessary death of the fish.

If you have any other questions about tetra fish or you want to share your stories about tetra fish or any other aquarium fish, you are always welcome to leave a comment.

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