Why Do Ember Tetras Swim Vertically? Find Out Here

Ember Tetra Fish have a natural instinct to swim up and down, or vertically. When Ember Tetras are swimming vertically it is often because they have Swim Bladder Disease. Swim Bladder Disease is an illness that affects the fish’s ability to control buoyancy, which ultimately causes them to float at the top of their tank.

It’s important to understand that there are other possible causes of vertical swimming including poor water conditions, genetic defects, infection, injury, or inadequate temperature. These can be difficult to diagnose without an expert opinion from a veterinarian who specializes in fish care. However, with prevention methods put in place, it is possible for your tetras to stay happy and healthy!

There are many other reasons why your pet may be swimming vertically as well – read on for more information!

Why Do Ember Tetras Swim Up and Down (Vertically)?

When ember tetras do not feel well, they can swim erratically. This means you will see them swimming up and down vertically. What are the various reasons that can cause this unusual behavior to leave you puzzled? Let us find out!

Swim Bladder Disease

Swim bladder disease can cause your ember tetra to swim frantically. The disease causes the ember tetras to feel sick. They are stressed out and the bladder is bulging out causing them to be uncomfortable. This is a reason why your ember tetra looks like it is adjusting in the water.

Poor Water Conditions

If your ember tetra fish are living in an environment that has poor water conditions, they could be swimming vertically. Poor water conditions can include low oxygen levels or high ammonia and nitrite toxicity.

Genetic Defects

There may also be genetic defects that cause vertical swimming behavior. This is typically seen when the pet was improperly cared for during development (for example – raised at too high of a temperature). Much like human genetics, there are some cases where this type of trait is passed on to offspring as well!


When Ember Tetras have an infection, it’s important to see your veterinarian immediately so that you can get the proper treatment. Infections caused by bacteria or fungi will often cause the fish to swim vertically as well.


If your Ember Tetra has an injury, it may cause them to swim at the top of their tank – or even mid-water! It’s important that you watch for any signs of external damage including; ripped fins, scrapes, and cuts on the body, ragged scales, etc. This is also a good time to check in with your veterinarian about potential infections from open wounds.

Inadequate Temperature

A drop in water temperature can be another reason why ember tetras are swimming vertically (or frantically). The ideal water temperature should be between 72 and 78 degrees Fahrenheit (22 – 26 Celsius). But if there is a sudden change in this range they will likely notice right away.

Inappropriate Food

Finally, your Ember Tetra fish may be swimming vertically because they are hungry! Feeding them at the right time is important for both their health and well-being. Not to mention it can help you prevent vertical swimming behavior as well! Read more about feeding practices here: https://tetra-fish-care.com/how-often-to-feed-tetra/

How To Prevent Ember Tetras That Swim Vertically?

Follow these steps in order to ensure that your tetras stay happy and healthy without resorting to vertical swimming behaviors!

Decoration and Hiding Spaces

You should ensure that there is an adequate population of hiding places like rock caves or dense plant life (Ember Tetras loves plants!). Providing this type of cover will ensure that your pets feel safe and secure.

Keep The Filter Running!

Make sure that you keep the filter running in your tank to provide a consistent current. Ember Tetra fish naturally live in flowing waters so you should try to replicate this in your tank as well. If you have a strong filter, it can actually help to keep your Ember Tetra healthy!

Keep The Water Clean!

Make sure that you do regular maintenance on your aquarium and change the water regularly. This will help keep ammonia and nitrite levels low which can reduce stress on your Ember Tetra fish!

Good Diet

Include a variety of food options in your Ember Tetra’s diet.

Include several different types of foods in the diet to prevent any picky eating. Ember Tetra fish like to eat bloodworms, brine shrimp, daphnia (water flea), plankton, and tubifex worms.

Change The Water Frequently

Ensure that the water is properly filtered and changed regularly. This can include a 50% – 70% weekly change of water for smaller tanks. Moreover, it can be up to 25% every two weeks in larger aquariums (depending on bioload).

Maintain The Water Temperature

Finally, make sure that the water in your tank is properly heated. The ideal temperature should be between 72 and 78 degrees Fahrenheit (22 – 26 Celsius).

Lastly, keep your tank at an appropriate temperature by using an aquarium heater if necessary.


Why Do Ember Tetra Swim At Top Of Tank?

Common Reasons Behind Ember Tetra Swimming At The Top Of Their Tank:

  • They are trying to find food! This is often due to incorrect feeding practices. Feeding your pet at the right time, and in the appropriate amounts will help prevent this behavior from happening. But if you aren’t sure how often or what types of foods they should be eating.
  • Their tank could have poor water conditions like low oxygen levels (if there aren’t enough aquatic plants) or high ammonia/nitrite toxicity. Poor water parameters can also cause stress. It may lead them towards swimming near the top of their tank as well! Make sure that you regularly test for these issues with your local pet store or online retailer.
  • They are trying to find a mate! If you have other Ember Tetras in your tank, they may be swimming near the top of their home. They are looking for another member of their species – especially during mating season!
  • The water temperature is too low! Similarly, make sure that you keep your aquarium between 72 and 78 degrees Fahrenheit (22 – 26 Celsius) year-round to avoid this issue.

How Do You Tell If Your Ember Tetra Is Stressed?

Finally, it can also be difficult to determine whether your ember tetras feel stressed out without seeing them swim in the wild. If you notice that your tetras are swimming vertically, or in a frantic manner, there is likely an underlying reason for it! For more information on how to tell if your ember tetra feels stressed out please visit this article:

There are a few key signs that can indicate if your Ember Tetra is stressed. One of the most common is when they start to swim vertically. You may also notice that they are swimming faster than normal, or hunching their backs. If your fish are gasping at the surface of the water, this is another sign that they are not feeling well.

  • Black patches on the skin
  • Excess mucous production
  • Hanging at the bottom of the tank without moving much while breathing rapidly Physical signs aren’t always easy to spot, but you can look out for:
  • Red or white patches on the body, fins, or gills
  • Excess mucous production (e.g., around the eyes and mouth)
  • Hanging at the bottom of the tank without moving much while breathing rapidly. If your fish display some or all of these signs, they may be stressed out. Take action immediately to identify the underlying cause of stress and treat accordingly!


Why do your ember tetra fish look like they are swimming vertically or in a frantic manner?

There is likely an underlying cause for this type of behavior – and it’s important to determine why. Generally, most cases can be resolved by changing the environment that your pet lives in, ensuring proper water filtration, and feeding them appropriately!

Moreover, to prevent ember tetras that swim vertically, you have to maintain the proper water parameters, good food, water temperature, and so on!

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