Tetra Fish Guide

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If you’re looking for a fish that’s low maintenance, isn’t costly to invest in, but still offers style and beauty to your aquarium, then we have just the creature.

Tetra fish are widely known for their beautiful colors, small size, and the mesmerizing way they swim together in schools.

Perfect for both beginner and advanced aquarium hobbyists, the Tetra will make an adorable addition to your aquarium.

Although they are undoubtedly an easier fish to care for, there are a few things to consider before you take the plunge and get a school of your own.

Where can you find them? How aggressive are they towards other fish, and exactly how many do you need to buy at once?

Here’s everything you need to know about how to properly care for a Tetra.

Tetra Fish: Origins and Appearance

Tetras are native to the warm freshwaters of Africa, Central America, and South America.

They are social fish that thrive in schools of six or more.

The name “tetra” was given to them because of the unique shape of their tiny teeth.

When given proper nutrition and a clean environment to live in, Tetras can live for up to ten years, making them a worthwhile investment if you are on a budget or don’t care to change out your collection regularly.

neon tetra fish
By Kyknos (CC BY 2.0 licence)

The adult Tetra can grow between 1.5 to 2 inches in length. The male Tetra is slimmer than their female counterparts, which are plumper in the belly.

Their brightly colored bodies come in an array of colors including (but not limited to) red, black, white, silver, and blue.

Tetras are top feeders, meaning that they will eat whatever lands on the surface of the water.

These fish are docile but lively, and compared to other freshwater fish, they are surprisingly hardy. This makes them a lovely choice if you’re introducing an aquarium to a child or if you don’t have the time to devote in babying a new tank. Their striking colors and mild temperament make them a popular pet to have.

Tetra Fish Types

There are a huge number of different tetra fish varieties. Here are a selection of the most popular and common:

  • Neon tetra fish
  • Glowlight tetra
  • Cardinal Tetra
  • Penguin tetra
  • Harlequin tetra
  • Rummynose Tetra
  • Ember tetra
  • Red eye tetra
  • Splashing tetra
  • Black tetra
  • Serpae tetra
  • Diamond tetra
  • Lemon tetra
  • Black phantom tetra
  • Congo tetra
  • X-ray Pristella tetra
  • Bleeding heart tetra
  • Emperor tetra
  • Silver tip tetra
tetra fish filter
Serpae Tetra. By Faucon (CC BY-SA 2.5 licence)

Some cracking names in that selection!

Acquiring Your Tetras

Luckily, Tetras are sold at most commercial pet stores, making the process of purchasing them relatively easy.

There is also the option of ordering them from a breeder, which is a great choice if you want to ensure that your Tetras are selectively bred.

Because Tetras are highly social fish, it’s not wise (or recommended) to get one by itself; you will need to get a school of between six to ten fish so that they won’t succumb to loneliness.

Tetras aren’t too expensive and some pet stores may have deals to where buying more fish reduces the price. In the case of the Tetra, the more the merrier!

Tetra Fish Care

Tank Requirements

Since Tetras must be kept in a small school, you will need to invest in a large tank.

The rule of thumb is that there needs to be one gallon of water for every one inch of fish. A 20-gallon tank can easily fit a school of ten small Tetras.

A Tetra tank should be positioned on a sturdy surface away from any windows. It would be best to invest in an aquarium light with a timer, and this timer should be set to have between ten and twelve hours of light per day.

It would also be wise to invest in an air pump to boost oxygen levels in the water.

The water should be kept between 74 and 78 degrees F with soft conditions and a low pH level. If you plan on having a tank with just Tetras, then having a slightly higher pH isn’t detrimental, but the lower it is, the better.

Put an inch to two inches of gravel at the bottom of the tank. It’s fine to decorate your tank with little statues, figurines, and plants so long as they don’t take up too much space.

Tetras need plenty of room to swim around, and a crowded tank will stress them out.

Use live plants instead of fake ones as this helps to balance the bio nutrients and chemicals in the water.

tetra fish food
Cardinal tetra (By Ltshears, CC BY-SA 3.0 licence)

Tank Introduction

Like with any fish, tetra fish shouldn’t be immediately introduced to the tank, which could lead to stress and diminish the chances of your fish’s survivability.

Make sure your tank has been given enough time to be treated and that the water conditions are just right before putting them in.

Ease your Tetras into their new home by placing their bag in the water for ten minutes. This makes it so that the temperature of the bag will begin to match the temperature of the water in the tank.

Next, open one side of the bag and put one cup of tank water into it, repeating this process slowly until your bag is filled with up to four cups of tank water.

Then get a net and transfer your Tetras into the tank. This method greatly increases your Tetras’ chances of survivability.

Tetra Tank Mates

Tetras are docile fish, so any other calm-natured freshwater fish will be a good partner for them.

However, as an act of caution, you should avoid having a long-finned fish as a tank mate because of the possibility that the Tetras will nibble on their fins out of curiosity.

Since they typically eat bloodworms as a favored treat, they’ll be attracted to the strange movements of a flowing tail and want to sample it themselves.

Save yourself the trouble – and the trauma, with children – by warding off temptation.

Tetra Fish Food

If you’re a beginner with aquariums or don’t care to invest a great deal, having a finicky fish can be troublesome. The good thing about Tetras is that they will eat just about anything, making them easy to feed.

They should have a mix of frozen and live foods for an optimal diet.

Fish flakes, brine shrimp, krill, plankton, daphnia, and beefheart are great sources of food. Bloodworms are tasty Tetra treats and can be put live or frozen into a dispenser for them to snack on.

Make sure you feed Tetras small portions to fit their little mouths; if they can’t munch on it with relative ease, they’re prone to starving themselves.

Watching them hunt the live bloodworms will definitely be a fascinating experience, but at the minimum, typical fish flakes will be enough to keep them happy.

As mentioned before, Tetras are top-feeders and will eat whatever lands on the surface of the water. Feed them whatever amount they will eat within three minutes, then stop.

Any food that the Tetras don’t eat will sink to the bottom of their tank and become detritus along with their waste, which will dirty their tank quickly.

Be sure not to overfeed your Tetras to avoid this. Feed them at least twice per day.

Take a look at this video on how to care specifically for neon tetra fish:

Tank Maintenance

The key to a healthy fish is a clean tank, so close attention needs to be given on a regular basis.

Water temperature should be checked daily, and other tank specifications should be checked weekly.

The ideal water conditions for a Tetra are pH levels between 6.5 and 7.8, nitrite levels at 0, nitrate levels below 40 ppm, ammonia levels at 0, and alkalinity at 80 ppm.

10% to 25% of the water volume of the tank should be changed out twice a month or every two weeks.

In this sense, they’re not very different from goldfish, but offer a wider variety of entertainment.

Whether it’s watching the school swim in sync or letting them loose on bloodworms, Tetras are happy with little maintenance but thrive with a bit of pampering.

Health Concerns

Just because the Tetra is a hardy little fish doesn’t mean that they aren’t susceptible to disease.

Anchor worms can become a threat to your Tetra’s health. This is indicated by whitish green threads coming off your fish’s scales as well as the fish constantly scratching against glass or decorations.

Treat your aquarium and fish with formulated anchor worm treatment, which should be an easy process lasting no more than a week or two.

Fungus is triggered by stress and/or parasites due to poor water quality. Your Tetra will have gray or whitish growth on or between their scales.

tetra fish
Black neon tetra (By Debivort, CC BY-SA 3.0 licence)

In this case, you need to quarantine the affected fish and treat them with commercial fungal treatment, and you need to conduct a partial water change in the aquarium.

Don’t worry – while they are social creatures, they won’t suffer too badly from being isolated for treatment.

Ich is a common fish ailment that is triggered by stress. White spots appear on the scales and the fish will scratch against glass or decorations.

Ich can be treated in three ways: raising the water temperature for ten days, using commercially formulated ich treatment, or adding two to three teaspoons of aquarium salt per five gallons of water for ten days.

Fin/tail/mouth rot is caused by fish bullying and/or poor water quality. This is indicated by a dull appearance and frayed fins. If multiple fish inhabit the aquarium with your Tetras, then remove the bully fish.

Often times this will not be another Tetra, but one of their tank mates which may be more aggressive. Treat the sick fish with a partial water change and bactericide.

Most ailments can be prevented by ensuring that your Tetras have a clean environment free of stress.

With proper care and attention, Tetras will flood your tank with plenty of life, fun, and enjoyment.

What’s your experience with tetra fish?


Featured image is by Faltasian (CC BY 4.0 licence)

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