Why are my neon tetras dying?

By Nadine Oraby | 2020 Update
Despite the popular opinion that fish are the easiest pets to keep, they are, in fact, the most prone to dying. Here is all of my research on why neon tetras meet an early death in aquariums.So, why are your neon tetras dying? Neon tetras die due to sudden changes in water conditions and temperature. Changing water conditions usually leads to Neon Tetra Disease and this causes their death. If your neon tetras are dying, monitor the water parameters. There are many reasons why your neon tetras are always dying, let us delve deeper into how to take precautions to avoid this situation.

Neon Tetra Care – Dying Issue? Tank Mates? (Video)

What are the symptoms of a dying neon tetra?

It is not a difficult task to detect a dying neon tetra.because they are playful tricky fish that swim in schools all around the aquarium. They adopt a certain behavior which would ring a bell if it ever changes all of a sudden.Even though neon tetras could live up to ten years, they tend to die easily with the slightest change in the water and tank conditions. If there is any change in the water chemistry, the fish would start experiencing stress, depression and would easily get infected with diseases.Any disease that infects neon tetras can lead directly to their death. They are extremely sensitive creatures and this requires you to be very protective and very keen on keeping the water chemistry constant under all conditions.There are many symptoms that show on your neon tetra which indicate that it is about to die very soon.The symptoms of a dying neon tetra are:
  • Stress
  • Restless neon tetras
  • Swimming in abnormal patterns
  • Inability to raise itself in the water


First off, we are going to discuss the first symptom that is quite easy to detect in a dying neon tetra.It is very important to know that a lot of things could cause stress to a neon tetra. Stress is the first thing that occurs to a neon tetra whenever it goes through any unsuitable sudden change in the water chemistry and the tank conditions.Not taking good care of the water’s cleanliness makes it easier for bacteria to infect the fish with various diseases that would end up killing them mercilessly. Bacteria make the water very toxic due to the wastes of the fish, the food remains or the ammonia level in the water. The presence of ammonia in the tank water can not only make the neon tetras stressed, but can also kill them within a matter of a few days.In order to guarantee that the water is bacteria-free, use Stress Zyme in the water to purify it and improve its conditions. Moreover, salting the water could be a good solution as well; it would reduce the risk of intoxicating the fish.If you had neon tetras that died in a tank, separate the remaining ones immediately from that tank so you can purify the water.

Restless neon tetra

The second symptom of a dying neon tetra is a restless fish which does not act normal like a typical neon tetra. However, mark the difference between a restless fish and a fish that is uncomfortable.Neon tetras could become restless on the first day you introduce them to their new home. Most of them suffer from tank shock. It is normal for a neon tetra to feel uncomfortable after changing its habitat all of a sudden.We mentioned that neon tetras are very sensitive to any changes, so do not feel surprised or confused when they act restless in a new environment.However, restless neon tetras also could indicate that the fish is sick and dying. Actually neon tetras could die just because they could not adapt to their new home.In order to avoid this from happening, you will need some patience to carry out a certain process to introduce the neon tetras to their new aquarium.First, you can let the bag of neon tetras float on the surface of the tank’s water to make them familiar with it. Then allow the tank’s water to get into the bag of neon tetras slowly every five minutes or so and repeat the process again for an hour.Later on, you can finally release the neon tetras into the tank and enjoy their interesting swimming patterns. It is quite a lot to do, right? But it would not be annoying if you love your fish. Just imagine you were in the fish’s shoes and you had to adapt to an unfamiliar setting, does it feel that bad now?

Swimming in abnormal patterns

Usually neon tetras swim in fixed patterns. The more time you spend watching them, the more you will get used to their synchronized swimming patterns.By keeping neon tetras for a few weeks, you would become a pro at detecting any strange patterns. When such a time comes, it should alarm you.Number one; it is a sign of stress indeed.Number two; it is a sign that the neon tetra is not following its school, is sick or suffering.Number three; it is a sign your neon tetra is showing symptoms of dying soonTherefore, you need to hurry up and check what is wrong with the water, tank or lighting. Maybe the particularly restless neon tetra might be getting bullied by the other fish and might not be welcomed in their school. Resultantly, it would get left out and might swim in such an odd manner as if the fish is drunk or swimming in circular patterns.In this case, take precautions and monitor the water parameters. Always look for an explanation whenever you come across an odd behavior that your neon tetras have started to adopt out of the blue. You will usually find an answer to your questions as long as you keep an eye on them and search for information to educate yourself more.It is always better to enrich your information about how to take better care of your pet fish in general.

Not raising itself in the water

This is also one of the symptoms of a dying neon tetra. You would find it always swimming at the bottom of the tank and not being able to raise itself in the water.Moreover, at other times, you would find a neon tetra floating at the surface of the water and unable to swim at the bottom of the tank as well.Both cases reflect that there is something wrong with the fish.  In order to prevent further problems with the rest of the fish, separate the sick fish into another bowl and put it under observation for 24 hours.If it does not change its abnormal swimming behavior, ask for the pet store’s help as they would surely be able to provide you with some expert opinion.

Related Questions

Why does a neon tetra suddenly lose its color? If your tank has too much bright light and no plants, this could stress your neon tetras out because they can only function in shaded and dark places. Moreover, neon tetras often turn transparent if they feel unsafe, threatened or sometimes just because the lighting is dim. So in this case, the color fade is normal.Do neon tetras get bloated? Yes, it is a symptom of disease as well. But first of all, mark the difference between a bloated neon tetra and a curvy one with a larger belly. A curvy neon tetra with a larger belly is a healthy female neon tetra which is carrying baby fish and you do not need to worry about that.Related Posts Other sources

1 thought on “Why are my neon tetras dying?”

  1. My neon is at the top of the water at all times away from the other 7. I got a tank that is too hard to keep care of. Now only 3 neons including him.


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