Tetra Fish Basic Care Guide

Introducing the Beginner’s Guide to Tetra Fish Basic Care. We tell you the fundamental knowledge to successfully care for your school of tetras.

Tetras are very easy to care for and can be housed with almost any other non-aggressive species.
The common name Tetra refers to many species of small freshwater fish that belong mainly to the biological family Characidae.
Among all, the most popular fish is the Neon Tetra Fish characterized by its bright colored body that adapts very well to the artificial habitat.
These fish respond well to good nutrition and a clean environment, so with proper care, they can live 5-10 years.
Stay with us and find out everything about basic Tetra care you should know to keep your Tetra fish healthy.
Tetra Fish
They are among the most common types of freshwater fish found in home aquariums, as you can see here. They are relatively small aquarium fish.
They mainly belong to the Characidae family, but we can also find species from the Lebiasinidae, Alestiidae families … Tetras are toothed fish and their name “ Tetra ” comes from the unique shape of their teeth.
There are countless species of tetras. The most common for aquariums include T. Neon, T. Cardinal, T. Penguin, T. Harlequin, T. Rummynose, T. Glowlight, T. Ember, and T. Glowlight.
These species have beautiful colorations, vivid personalities, and are less sensitive to water conditions than other fish. They have a maximum size of 5 cm and can live up to 10 years in captivity if they are cared for properly.
The male of the species is slimmer than the female. Females are slightly thicker around the belly.
The most appreciated for the fish tank have brightly colored bodies such as red, white, blue, silver and black. People love to see their bright fluorescent colors when they swim in groups.
Tetra fish are good eaters, and their small size and nature means that they need a school in the aquarium.
These beautiful fish are some of the cleanest for an aquarium, creating very little bioburden when compared to, for example, Bettas or Discus. Still, it is necessary to provide a good quality filter like this to clean the water and make it hygienic for Tetra fish.
Natural Habitat of Tetras
The tetras cover a large geographical area, so we find a wide variety of species adapted to different ecosystems. We can find tetras of different sizes, types of water, colors or eating habits.
The vast majority come from the Amazon Basin and other river systems in South America. They mostly inhabit rivers and streams, although a unique species, the blind tetra, was discovered in a cave system in Mexico.
Life Span
An interesting fact is that if a fish lays eggs it lives a longer life compared to others that do not.
Tetra Fish Behavior

Despite these social preferences, schooling Tetras have some small fights that are not dangerous, but just a way to show their dominance over other fish and to intimidate them.
Tetra fish are not aggressive, but their occasional aggression is superficial. You will hardly see them fighting to the point of injuring each other.
Tetra Fish Size
Tankmates for Tetras
But there are a few exceptions, tetras serpae, for example, are prone to stinging fish with long tails. Others, like the Buenos Aires tetras, get quite large and are very active, which can intimidate smaller, more timid fish.
Ideal tankmates include other tetra species, platys, rasboras, mollies, small danios, pacific barbels, and guppies.
You always have to make sure that the species you want to keep cohabit well in your aquarium. It is best to always consult an expert before purchasing any new fish for your aquarium.
Tetra fish care
Let’s see the main indications to set up an appropriate aquarium for these beautiful fish.
The shoal
As a reference, we can consider the following pattern of the number of individuals with respect to the size of the tank: 10 tetras for a tank of less than 75 liters, 50 tetras in a 75-liter tank, 60 in a 100-liter tank, and up to 100 Tetra fish accommodated in a 225 liter tank will be an ideal situation.
As a breeder or owner you should keep a minimum of 10 Tetra fish together, otherwise they can get sick and die due to stress.
You should also keep in mind that you should not overpopulate the aquarium. Too many fish will decrease the quality of the water and the quality of life for your pets.
Tank
Still, for most tetras it can be installed in at least a 35 liter aquarium like this one.
Dark substrates and decorations will help accentuate the bright colors of your tetras. It is advisable to put a lid on the aquarium to prevent them from jumping if they feel scared or threatened.
You should also provide a gentle but steady current.
Also, keep these tips in mind:
- Place your aquarium on a sturdy stand and away from windows.
- Use a heater to make sure the temperature of the water.
- Place a lamp in the aquarium with a timer that shines for 10 to 12 hours a day.
- You should also get an air pump to increase the oxygen levels in the water.
General characteristics of water

Correctly cycling the aquarium is essential for a Tetra fish to thrive successfully. Let the tank mature as long as necessary before adding the fish.
Maintain good filtration and make the necessary water changes to maintain healthy water for your pets. Do not forget that the water must be conditioned.
Tap water contains chlorine and heavy metals, so use a water conditioner like this one to remove these agents.
Temperature
When it is warmer than 26°C, tetra fish will generally have a faster metabolism which will cause them to become stressed more easily. Your life expectancy will also be shortened.
If the aquarium is in a room with a temperature lower than 24°, use an aquarium heater like the one you see here to increase the temperature. There are exceptions like the Buenos Aires tetra that need colder water.
Levels of water chemical parameters
So while tank-raised strains tolerate higher pH or dH levels, lowering them will help them thrive.
For most tetras, the water parameters should be:
- The pH should be between 5.5 and 7. Captive bred Tetras can accept a lower or higher pH depending on the parameters of the water used in their hatchery. Be sure to check this out when purchasing your tetras.
- The relative hardness of the water must be between 3° and 8° dkH (50 ppm to 140 ppm). This will mimic the relatively mild conditions similar to those in the Amazon.
- Chlorine 0ppm
- Ammonia 0 ppm: Tetras are sensitive to ammonia spikes. They can lose color and breathe quickly.
- Nitrite below 0.5 ppm. 0 is ideal
- Nitrate > 40ppm. Nitrates should always be as close to 0 ppm as possible. Any reading below 40 ppm is adequate to keep Tetras. Elevated levels can be reduced by adding aquatic plants and increasing the number of water changes.
salt effects
For soft water fish like the neon tetra, excess salt is not a good option in the aquarium. But in controlled and prescribed amounts it can be added to treat some minor infections. Salt with iodine is good for them.
Check your water regularly to make sure hardness, chlorine, alkalinity, and pH levels are within healthy ranges.
Incorporate Tetra fish into the aquarium
- 1. Float the unopened plastic bag in the aquarium for 5-10 minutes. This will allow the water in the bag to equalize its temperature to that of the aquarium. The bags must be filled with oxygen, so there is little risk in leaving the fish sealed for a little longer.
- 2. After 10 minutes, open the bag. Gently pour a cup of aquarium water into the bag and let it sit for 5 minutes. Continue this process with 3-4 more cups of water. You may need to hold the bag to the side of the tank to prevent it from sinking.
- 3.Use a soft net to pick up the Tetras from the bag and gently place them into the aquarium. Discard the water in the bag.
This method will improve the survival of your Tetras remarkably.
Feeding Tetras
What do tetras eat? Most tetras are omnivores and will eat just about anything.
Tetras enjoy a variety of very small flakes or granules. Also, live or frozen bloodworms in a small feeder cone are an excellent treat for adult Tetras.
For best results, rotate your diet daily and provide only what you can consume in less than 2 minutes, once or twice a day.
Don’t overfeed your fish. If you add more than the fish eat, the uneaten food will rot at the bottom of the tank, dirtying the water.
Names for your fish
Selecting a name for your Tetra fish is one of the most important parts of fish care.
It helps you distinguish your fish so you can have better control over each individual in the school.
Tetra Fish Breeding

Purchase at least a dozen young tetras. Younger tetras have a much lower chance of contracting disease or becoming sterile.
Keep the conditions perfect for tetras. Sterility is the biggest problem with many species of fish, including tetras. In poorer conditions, reproduction is a much lower priority for tetras, who focus on survival.
Feed the tetras a varied diet of flakes, pellets, frozen and freeze-dried worms, and of course live worms and shrimp. Make sure to feed them twice a day to keep the Tetras in top health.
Match the Tetras by looking at the subtle difference between male and female. Females are generally slightly larger than males, with shorter dorsal fins and less saturated colors. Males are slimmer and often have extended fins and rays. They also tend to have a brighter, more saturated color.
Pair formation and courtship is the most difficult part of raising Tetras. Keep in mind the high odds of defeat, but don’t give up. Constantly try new partners in the breeding tank until a successful match is found.
Incorporate some fine-leaved plant or floating moss into a small 5-gallon breeding tank. Make sure the water is very soft and with a stable pH similar to that of the main aquarium. Place a breeding pair in the tank and monitor their progress.
Tetras generally spawn in the early hours of dawn. You will notice the plant lined with very faint black dots that are actually Tetra eggs.
If you are successful, remove the parent fish and feed the fry live infusions when they hatch 12-48 hours after spawning.
It eventually uses newborn brine shrimp, nauplii and micro worms. Once the fry are large enough, feed them powdered flakes.
Congratulations if you get to this point, breeding Tetras is extremely difficult.
Buy Tetras
An excellent tetra for those starting out with their first tropical fish is the Neon Tetra. These are easily identifiable by their bright red and neon blue stripes.
Tetras are best purchased as a school of at least 10 individuals of the same species. This will help the fish to be safer in the tank and less stressed.
tetra fish diseases

These fish are quite hardy, but they can also catch diseases, even when you’re doing everything perfectly. This is why you must be attentive to the signs of illness.
Some of the common symptoms that show your Tetra fish are sick are:
- Fish skin discoloration with dull color
- The fish are not calm, they show a lot of restlessness
- A lumpy body accompanied by cysts on the skin
- Fish body looks unbalanced, may be due to bent spine
- Swelling
- Irregular swimming patterns, look drunk
- raised scales
- loss of appetite
Some of the most common diseases among tetra fish are:
- Anchor worms are introduced into the water by infected fish. You may see affected fish scratching themselves against glass or decorations, or you may notice whitish-green threads coming off their scales. To treat anchor worms, you will need to treat the entire tank and all the fish. Add a commercially formulated treatment for anchor worms.
- Fungus problems usually appear when fish are stressed, have parasites, or live in poor water conditions. You will see a gray or whitish growth on or on the scales. Quarantine infected fish and perform a partial water change in the main aquarium. Treat infected fish with a commercial fungal treatment.
- Ich is one of the most common fish diseases, and it usually attacks stressed fish. You will begin to notice white spots on your fish, and they will begin to scratch themselves. You can treat them in many different ways:
- Increase the temperature for about 10 days to accelerate the life cycle of the parasites.
- Add 2 to 3 tablespoons of aquarium salt per 20 liters of water for about 10 days.
- Use a commercially formulated ich treatment and follow the directions.
- Fin, tail and mouth rot is a common bacterial infection that can cause fin, tail and mouth rot. It is most common when there is a bully fish picking on other fish and when the water quality is poor. You will notice frayed fins, faded color, and general deterioration of the tail or fins. If you notice a bully in the tank, remove it so you can treat the fish with the rot. To treat sick fish, perform a partial water change, add aquarium salt to the tank, and consider treating the water with a bactericide such as Melafix.