Ammonia in Fish Tank – Causes, Symptoms, and Treatment

ammonia in fish tank

Ammonia poisoning is a fatal disease found among the fish in the tank, which often causes death. The ammonia level in the fish tank should be null as to avoid any kind of poisoning in the tank. Mostly, a shallow level of ammonia is not so dangerous for the fish. However, it can cause a minute level of problem. Whereas, if there is high ammonia in the fish tank, the fish can eventually succumb to death.

Now, the most crucial issue is how to check ammonia in the fish tank. In this case, one can always consider an ammonia test as the best option for it. Also, one needs to have an understanding of the symptoms of ammonia.

To know more about different Saltwater and Freshwater Aquarium Fish Diseases, click this article “Aquarium Fish Diseases: Causes, Symptoms, and Treatments“.

Ammonia in Fish Tank Symptoms

One can detect the presence of ammonia in the tank or ammonia poisoning in the fish through several symptoms. Ammonia poisoning generally causes some substantial changes in the fish. It gives a clue of the presence of ammonia poisoning in the fish. The symptoms of ammonia poisoning don’t appear immediately. It may take a few days to emerge of even a period.

Now, ammonia poisoning is not at all a standard issue as it can lead to the death of fish. Thus, one should be very careful and aware of the emerging ammonia in the tank. There can be various symptoms of ammonia in the fish tank.

  • Firstly, one can mark the point of the fish moving towards the upper surface of the tank to access air. The water present in the tank is not preferable for the fish. The fish may face particular difficulty while breathing in the tank due to the presence of ammonia.
  • The second pronounced symptom of ammonia poisoning can be the change in the color of the fish. The fish may turn dark when the ammonia is reacting to its body. So, one can get an idea of ammonia poisoning developing in the fish.
  • Now, the gills of the fish may even turn purple, red, or lilac in case of ammonia poisoning. Also, at times the gills may start bleeding or appear to be bleeding due to ammonia poisoning.
  • One may also be able to see an emergence of red streaks on the fins and body of the fish. It is usually caused due to prolonged damage to the fish’s tissue. It thus leads to bloody patches on the body and fins of the fish or a torn fin.
  • Also, the fish’s brain can get damaged. The organs and the whole Central Nervous System of the fish can get affected due to ammonia poisoning. At times, the ammonia poisoning can always lead to internal and external hemorrhage, thus, causing the death of the fish.
  • Lastly, one can also see the fish getting lazy, weak, and lying at the tank’s bottom. It can be the result of the decreasing appetite of the fish, which is thus caused by ammonia poisoning.

This way, the body functions of the fish gradually fail and cause fatal conditions constituting death. It becomes essential for one to understand the basic reason as to what causes ammonia in the tank. This way, we can take steps to check the ammonia present in water and even check the ammonia poisoning which has developed in the fish.

What causes Ammonia in Fish Tank

Ammonia is a fatal problem and acts like a fish killer. It is essential to develop knowledge of what causes ammonia in the fish tank and take precautions accordingly. Now, it may develop in the tank due to several reasons.

New Fish Tank

Firstly, ammonia poisoning can happen as one sets a new fish tank. In this case, it usually takes time for the tank to establish the nitrogen cycle. Thus, initially, the water contains ammonia, which can be very dangerous for the fish.

Also, in the old tank, ammonia can be traced as a result of the failure of it’s purifying filter. The failure may happen due to different reasons, that is, either power issue or any mechanical problem. Even dirty water or changing water conditions can cause ammonia to rise in the fish tank. For these reasons, regular checking of the water becomes compulsory.

The Rise in pH Level

Another reason for ammonia poisoning is that the rise in the pH level of the tank. Typically, the water pH level for the fish tank should be 7. As the level goes above this, it becomes dangerous for the fish.

Furthermore, tap water can be one of the causes of ammonia poisoning. Chemically treated tap water can damage the gills of the fish. Low levels of ammonia are not so harmful to the fish. The level of the poison is directly proportional to the ammonia level in the tank. We know that companies generally prefer chemicals such as chloramine to treat water. They say it one of the best methods for purifying the city water. In contrast, this water is very harmful to the fish in the tank.

Too Many Fish

Stocking the tank with too many fish at once can also be one of the causes of ammonia poisoning. Fish is responsible for the rise of ammonia. Whenever it is that the fish eats something, it generates certain by-products in its body. Now, as these by-products enter their blood, they are released into the water through the gills of the fish. Thus, this gradually increases the ammonia levels in the tank.

Also, the organic matter in the tank can be one primary reason for ammonia poisoning. As the organic matter decomposes, it eventually leads to an increase in the ammonia level in the fish tank. These decomposed matters can be plants present in the tank, excretion from the fish, or even the excess food in the tank.

Overfeeding Fish

Even overfeeding fish can result in ammonia poisoning. It leads to more amount of by-products accumulating in the tank through the fish’s body. Moreover, as the fish tank is left dirty, it gives rise to the development of bacteria. The bacteria prefer to stay in the water with ammonia in it.

Thus, these are the fundamental causes while eventually leads to ammonia in the water. Ammonia poisoning in the fish’s body leads to severe and dangerous problems. One needs to be aware of these causes as it becomes very helpful for further precautions.

Now, as we are aware of the causes and symptoms of ammonia poisoning in the fish, we can take specific steps to treat ammonia in the tank and then ammonia poisoning.

How to check ammonia in the fish tank

Ammonia in the fish tank won’t go down instantly. One requires specific steps for reducing ammonia. It becomes very difficult to get rid of ammonia poisoning once it has developed. It is crucial to take certain measures to check ammonia in the fish tank before it develops.

Gravel from an Existing Fish Tank

Firstly, we recommend using the gravel of a pre-established fish tank. It is very hygienic, so that is doesn’t lead to some more severe issues. Since this gravel has already developed anaerobic bacteria, this bacteria further helps to reduce ammonia. One can take almost a handful of this gravel and then move on to placing it at the very bottom of the tank so that the bacteria may be useful in reducing ammonia in the fish tank. Also, this becomes an essential step in the beginning. At the same time, in a newly set up tank, it generally takes time to establish its complete nitrogen cycle. Thus, the gravel from the old fish tank can be adequate to reduce ammonia in the fish tank.

Avoid Placing Too Many Fishes in a New Tank

Secondly, one should always keep in mind that initially, it is crucial to put just two fishes in the tank at a time. It is essential as the tank had not developed the working of the nitrogen cycle at this point. Placing more than two fish at this point can lead to a higher level of ammonia effect on the fish as the fish will go on to excrete more. Thus, this excretion, eventually, paves the way for the existence of harmful bacteria and also ammonia in the fish tank. Also, implement this in the old tank as well. One should remember not to overload the tank and place only two fish even after the tank set up.

Do Not Overfeed the Fish

Thirdly, it is very crucial not to overfeed the fish. As one goes on to increase the amount of food, it gradually leads to an increase in the number of by-products in the body of the fish. Then, this by-product enters into the blood and thus mixes with the water through the gills of the fish. As a result, these by-products lead to the development of bacteria, which then increases the ammonia levels in the tank.

It is also very essential to remove any amount of left out food from the tank as it may add up to the amount of decomposed matter in the tank. These decomposed matters, further, leads to the generation of ammonia in the water, and now the bacteria which are usually born in ammonia filled water are developed.

Clean the Fish Tank Regularly

A fourth important factor in reducing ammonia is to keep cleaning the tank regularly. One needs to clean the tank either once or twice a week. It helps to keep a check on the ammonia level in the fish tank.

Partially Replace Water in the Fish Tank

The fifth preventive method of checking ammonia in the fish tank is to keep on changing the water in the tank partially. Also, one can test the water for ammonia. In case of extreme conditions, one can even use an ammonia detoxifier for clearing up ammonia from the fish tank. An Aqueon Ammonia Cartridge Mini Pad, available on Amazon, can be used for removing excess harmful matters from the fish tank and also the toxic ammonia present in the tank. The product promotes the existence of a very healthy environment for the fish to survive in the tank.

However, in case the ammonia poisoning had already developed in the fish, it becomes complicated to cure the diseases. The diseases really can prove to be deadly, causing an eventual death of the fish in the tank. Notwithstanding this, one can take some crucial steps to get the fish a relief from ammonia poisoning and made the disease vanish.

Treatment To The Disease of Ammonia Poisoning

Control pH Levels in the Fish Tank

Although, the presence of more than one ppm of ammonia in the tank can be dangerous, when the ammonia poisoning had already affected the fish, any amount of ammonia in the tank turns out to be deadly. Thus, it immediately needs to be checked. Also, as one reduces the level of pH in water, it provides instant relief to the fish. Use acidic water to stabilize ammonia.

Further, one can use a chemically proven pH control commodity to neutralize the ammonia present in the fish tank. More importantly, one needs to strictly follow the advice of not feeding the fish while treating it for ammonia poisoning. While in case the poisoning has reached a very high level, one should continue not to feed the fish for a more extended period to reduce the ammonia waste.

Do Not Add More Fish during Treatment

Lastly, one must remember not to add any more fish in the tank during the ongoing process of ammonia poisoning treatment. If one adds a new fish in the tank, it may cause a hindrance in the treatment procedure. Thus, take these steps in case the disease has already affected the fish’s body. If one doesn’t take certain precautions, the disease may eventually affect the metabolism of the fish’s body. It can even breakdown the nervous system of the fish. Therefore, to avoid any such situation, preventive measures need to be followed strictly.


Therefore, in the end, we can sum up the idea of how to check ammonia in the fish tank. As one becomes aware of the primary symptoms, which generally lead to an increase in the ammonia level and poisoning, one can accordingly take certain measures to reduce ammonia in the fish tank.

Also, the basic know-how of what causes ammonia in the fish tank is necessary for prevention. Negligence is the main reason for ammonia in the fish tank. It can be very detrimental and can cause serious diseases in the fish. Also, one has to follow the basic measure of cycling the tank for lowering the ammonia level in the fish tank.

To know more about different Saltwater and Freshwater Aquarium Fish Diseases, click this article “Aquarium Fish Diseases: Causes, Symptoms, and Treatments“.