Ammonia Poisoning in Bettas: Causes, Symptoms, and Treatment

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By Linh Nguyen Updated on 02 Feb 2023

Betta fish are popular pets and many people enjoy having them in their homes. However, ammonia poisoning can be a big problem for these fish, leading to serious health problems or even death. In this post, we'll take a look at what ammonia poisoning is, the symptoms to watch out for, and how to treat it. We'll also share some tips on how to prevent ammonia poisoning from happening in the first place. So if you're a betta owner, read on! You don't want to miss this important information.

A betta fish with ammonia poisoning

A betta fish with ammonia poisoning

1. What is ammonia poisoning betta?

Ammonia poisoning is a condition that can occur in betta fish when the level of ammonia in their water becomes too high. Ammonia is produced by the breakdown of organic matter and is present in all aquariums, but it is especially harmful to betta fish because it builds up quickly in small spaces.

Betta fish are very susceptible to ammonia poisoning because they are a tropical species that come from waters with very little dissolved solids. Besides, they are very sensitive to sudden changes in water quality.

Ammonia poisoning is one of the most common causes of death in betta fish, and it can happen very quickly if the levels of ammonia in the water rise too high.

The amount of ammonia present in the water is measured in parts per million (ppm). The recommended level of ammonia for betta fish is 0 ppm. However, levels as low as 0.5 ppm can be harmful to betta fish.

2. Causes

There are many possible causes for your betta to have ammonia poisoning in the water, but luckily it's easy enough that you can find out what is wrong with him. Detecting the causes is important because it will tell you what needs to be done to fix the problem.

Here we go!  The common culprits behind this problem could be:

Overfeeding: The most common cause of ammonia poisoning is overfeeding. When fish are overfed, they produce more waste than the filter can remove from the water. This waste then breaks down into ammonia. 

Insufficient, damaged, or outdated filter: Insufficient filtration can also lead to ammonia buildup, as filters help remove ammonia from the water.

Poor inlet water quality: Poor water quality is another possible cause, as ammonia can build up in the water if it is not regularly changed. 

Overcrowding: Overcrowding can also contribute to higher levels of ammonia, as there is more fish-producing waste in a smaller space.

Aquarium decorations: Ammonia can also be introduced into the water from unclean tanks or decorations, as well as from using tap water that has not been properly treated. Driftwood in the aquarium can also decompose and produce more ammonia than usual. If there is too much ammonia in the water, it can poison the bettas.

Undergravel filters: Undergravel filters can also cause ammonia problems, as they can trap debris and waste under the gravel, leading to the decomposition and release of ammonia.

Lack of microorganisms: A lack of microorganisms can also cause ammonia poisoning, as these tiny creatures help break down waste and prevent it from building up.

Residual cleaning chemicals: When cleaning products or chemicals are used in the aquarium, they can cause the water to become more acidic. This can lead to ammonia poisoning in bettas because the fish are not able to process the ammonia properly and it builds up in their system.

Causes of ammonia poisoning on your betta

3. Symptoms and pictures

Betta fish are very sensitive to ammonia and can easily succumb to poisoning if exposed to high levels. Ammonia poisoning is one of the leading causes of death in betta fish, and it can occur very quickly if they are exposed to high levels of ammonia.

Here are the symptoms when your betta has ammonia poisoning.

Lethargy: Betta fish who are suffering from ammonia poisoning will often appear to be lethargic, or sluggish. They may have a hard time swimming, and may even float at the surface of the water. Their fins may appear to be clamped together, and they may be listless and unresponsive.

Rapid and/or labored breathing: Bettas with ammonia poisoning will have rapid and/or labored breathing. This is because the ammonia is causing irritation to their respiratory system. In severe cases, the betta may be gasping for air and may even have trouble staying afloat.

Swimming erratically: Betta fish that are suffering from ammonia poisoning will often swim erratically, as their nervous systems are affected. This can cause them to dart around erratically, or even to become tangled in plants or other objects in their tanks. In severe cases, bettas may even float upside down at the surface of the water, unable to swim properly.

Loss of appetite: One of the most common symptoms of ammonia poisoning in bettas is a loss of appetite. This can be caused by a variety of factors, including stress, poor water quality, and disease. If your betta is not eating, it is important to check the water quality and make sure that there is no ammonia present.

Reddening of the skin and/or fins: One of the most common symptoms of ammonia poisoning in bettas is reddening of the skin and/or fins. This is caused by the ammonia in the water irritating the fish's skin and fins. Ammonia can also cause burns on the fish's skin and fins, which can lead to inflammation and swelling. In severe cases, ammonia poisoning can even cause death. If you see any signs of reddening or burns on your betta's skin or fins, it is important to immediately remove them from the water and treat them with a gentle cleanser designed for fish.

Cloudy eyes: This is caused by the ammonia irritating the eyes and causing them to become inflamed. In severe cases, the inflammation can lead to ulcers or even blindness.

Clamped fins: The fins of a betta fish with ammonia poisoning will appear to be "clamped" close to their body. This is a defense mechanism to reduce the surface area exposed to the toxic ammonia levels in the water.

White spots on the skin and/or fins (ich/white spot disease): When the ammonia levels in a betta fish's tank rise too high, it can cause a condition known as "white spot disease." This is characterized by small white spots appearing on the fish's skin and fins. These spots are actually tiny parasites that attach themselves to the fish and feed off of its blood. As the parasite population grows, it can weaken and even kill the fish.

You can learn more about this disease through the article: Betta Fish Diseases: Ich (The White Spot Disease) - What You Need to Know

If you notice any of these symptoms in your betta fish, it is important to take action immediately and begin treating the poisoning. Ammonia poisoning can kill your fish very quickly if not treated. The sooner you catch and treat the issue, the better the chances are for your fish's recovery.

Symptoms and pictures of ammonia poisoning betta

4. Treatment

If your betta fish is suffering from ammonia poisoning, it is important to take immediate action to treat the condition. There are a number of different treatments that can be effective in treating ammonia poisoning, and the best course of action will often depend on the severity of the condition.

In mild cases of ammonia poisoning, simply performing a water change and adding a quality aquarium filter can often be enough to resolve the issue. If the ammonia levels in your tank are still high after performing a water change, you may need to use an ammonia-removing product such as Amquel Plus or Prime. These products work by binding with the ammonia in your tank water, making it safe for your fish.

In more severe cases of ammonia poisoning, your betta fish may need to be moved to a temporary hospital tank. This is a small, separate tank that is set up specifically for treating sick fish. The hospital tank should have very clean water and should be equipped with a quality filter. You may also need to use an ammonia-removal product in the hospital tank.

Your betta fish may also need to be treated with antibiotics if he has developed bacterial infections as a result of ammonia poisoning. Antibiotic treatments should only be used when absolutely necessary, as they can cause harmful side effects in some fish. If you do need to treat your betta with antibiotics, be sure to follow the instructions carefully and contact your veterinarian if you have any questions or concerns.

Ammonia poisoning can be a serious condition, but it is often easily treatable if caught early. Be sure to monitor your betta fish closely for any signs of illness and take action immediately if you suspect he may be suffering from ammonia poisoning. With prompt treatment, your betta fish should make a full recovery.

Betta fish ammonia poisoning treatment

5. Prevent ammonia poisoning

Preventing ammonia poisoning in bettas can be done in a few different ways.

  • First, make sure to keep their living space clean. This means regular water changes and vacuuming the gravel to remove uneaten food and waste.
  • Second, feed them properly. Overfeeding can lead to more waste and higher levels of ammonia.
  • Third, use a filter in their tank. Filters help to keep the water clean and reduce ammonia levels.
  • Finally, make sure that you are using the correct size tank for your betta. A too-small tank will cause ammonia levels to rise quickly.

By following these simple tips, you can help prevent ammonia poisoning in your betta fish.


Ammonia poisoning can be a serious issue for betta fish, and it’s important to be aware of the causes, symptoms, and treatment options. By following some simple preventative steps and being vigilant about water quality, you can help keep your betta healthy and safe from ammonia poisoning.  If you believe your fish may have been poisoned, please let me know in the comments below and I will do my best to help. Thanks for reading!

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