How To Get Rid Of Ammonia In A Fish Tank? 4 Safe Methods

Why is ammonia so bad for fish?

Ammonia is extremely toxic to fish. Elevated levels of ammonia in your fish tank can lead to convulsions and even death. This is because elevated levels of ammonia cause ammonia poisoning. Ammonia poisoning usually occurs when a new tank is not properly cycled or when a biological filter fails or is removed.

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Ammonia can poison your fish in two ways. First, elevated levels of ammonia in your aquarium water will directly affect your fish resulting in severe side effects such as stress, disease susceptibility, brain shutdown, and/ or organ failure. These effects often result in death after some time. Second, elevated levels of ammonia in your aquarium water will poison your fish by depleting oxygen levels. The kind of “poisoning” that will occur with the depletion of oxygen is suffocation. 

In short, what I am trying to say in so many words above is that ammonia is hazardous to fish in several ways. 

Signs of elevated levels of ammonia in aquarium water

If you have been paying attention to your fish then you know when it is okay and when it is not okay. When your fish is not behaving normally, it is usually a sign that something is wrong. Most of the time, the problem is usually in the water chemistry e.g. too much ammonia in the water.

Below are some of the signs you can use to tell if your fish is being poisoned.

  • Inflamed or “burned” eyes or anus
  • Inflamed gills
  • Gasping for air at the surface
  • Changing the traditional dwelling place
  • Lack of appetite
  • Lethargy especially for traditionally active fish

The list above is not exhaustive. However, it provides some of the most common signs of ammonia poisoning. These signs are all red flags and they say, “Something is terribly wrong. You better act now!” 

How to act if there are signs of ammonia poisoning

Once you detect ammonia poisoning, the easiest way to deal with it is to initiate a water change. There is always the temptation to add an ammonia remover to your fish tank because it seems like an easy way to deal with the problem but this is something you should try to avoid. This is because adding too many chemicals to your tank will make your fish’s immunity weaker.

In contrast, a water change will remove the ammonia from your tank water and give your fish fresh water to breathe and to recuperate. I will share with you more ways on how to deal with ammonia poisoning in a few moments.

How exactly to detect ammonia before poisoning occurs

Ammonia is the number 1 aquarium fish killer. However, it does not need to be. There are two main ways you can detect increased ammonia in your tank and take action before it is too late. 

  1. By using an ammonia alert sensor

There are several ammonia alert sensors on the market that you can purchase and use to automatically detect increased ammonia in your tank. The benefit of using an ammonia alert sensor to detect increased ammonia in your tank is that you do not have to do the test yourself. You simply need to set up the sensor and wait for the alert.

  1. By using an ammonia test kit

The method commonly used by aquarists around the world to detect increased ammonia levels is the use of ammonia test kits. There are literally dozens of ammonia test kits available online for sale. They can help you to detect increased ammonia levels any time you want.

By using either of the two methods above, you can detect increased ammonia quickly before ammonia poisoning occurs. In case you use either of the two methods above and you find that your tank has increased ammonia levels, there are several methods you can use to eliminate the ammonia. I discuss them in the section below.

4 safe methods you can use to remove ammonia and their advantages and disadvantages

  1. Change the water in your tank

Changing the water in your tank is the number one way to remove ammonia from it if you detect increased levels of ammonia. Normally, it is recommended that you replace about 20 percent of the water in your tank. Doing this reduces the levels of ammonia nitrite and other chemicals in the water by diluting them. If you already do this and you have still detected a spike in ammonia levels, you should increase the amount of water you replace weekly.

So instead of replacing just 20 percent of the water in your tank, you should aim to replace at least 50% weekly. Doing this will instantly reduce the levels of ammonia and nitrites in your tank water by diluting the water even more. And the reduction of ammonia and nitrites will be directly beneficial to your fish.

Moreover, the introduction of fresh water into the tank will inject new oxygen and this will enable your fish to breathe better.


  • This is a quick method for removing ammonia
  • It does not involve the use of chemicals 
  • It reduces ammonia and all other toxic chemicals


  • Not all ammonia in the water gets removed immediately 
  • Changing tank water is a bit challenging
  1. Reduce your fish stock and stop overfeeding your fish

If there is increased ammonia in your fish tank, one of the possible causes could be that you have overstocked your tank. Another possible cause could be that you are overfeeding your fish.

The more the merrier should not be your guiding principle when stocking your tank. It may be physically possible for you to house more than 15 fish in your home aquarium but you should not do it. You should not do it because fish need space. Moreover, when you have too many fish in a home aquarium, the amount of toxic waste (ammonia) they will release increases. So more fish equals more ammonia in the tank. Therefore, if your tank has too many fish, you should reduce your stock.

You may enjoy feeding your fish more than doing anything else in this world. However, you should not overfeed your fish. Because if you do, your fish will have more food to turn into waste. This will automatically mean more waste (ammonia) in the water. Moreover, if you overfeed your fish, they will not be able to eat everything and this will result in more and more fish food getting to the bottom of the tank and going uneaten. As this food decomposes, it will also release ammonia and increase ammonia levels in the tank water.

Therefore, to reduce the levels of ammonia in your tank, you should reduce your fish stock (if you have too many fish), and stop overfeeding your fish (if you have been doing so). 


  • This method works
  • It reduces the accumulation of ammonia in the tank
  • It is a free method to deal with increased ammonia
  • It makes it easier to maintain your tank and feed your fish


  • The method does not reduce the ammonia already in the water
  1. Clean and maintain your tank

When you notice increased levels of ammonia and nitrites in your tank, perhaps the number 1 thing you should do should be to clean and maintain your tank. Because 99 percent of the time, increased levels of ammonia and nitrites are usually indicators that something is not working right. And when something is not working right in your tank, it will most likely lead to the accumulation of waste. This will, in turn, lead to the accumulation of ammonia. Therefore, by cleaning and maintaining your tank, you should be able to get everything working right again and the levels of ammonia and nitrites reduced.

When cleaning and maintaining your tank, you should focus on the following things. First, you should maintain your live plants. Many people forget to maintain their live plants and this makes them ineffective at absorbing ammonia and CO2 and releasing oxygen. You can maintain your live plants by pruning them, by removing dead ones, and by adding some organic fertilizer.

Second, clean your filter. Your tank’s filter is supposed to be eliminating ammonia very time tank water goes through it. If it doesn’t then clean it. But make sure you don’t clean the beneficial bacteria in the filter. If you do, you will make the filter useless. If you don’t know how to clean your filter, call your local pet shop for guidance. 

Third, use a gravel vacuum. Uneaten food accumulating on top of your gravel will directly result in more ammonia in the water because it will eventually decompose and release the chemical. However, you can eliminate uneaten food every now and then by using a gravel vac. 

Lastly, clean everything inside the aquarium and then do a 50% water change. This will ensure the tank has significantly reduced ammonia.

As you can see from the points above, you can significantly reduce ammonia levels in your tank by cleaning and maintaining it.


  • This method is the best for removing ammonia
  • It makes sure the tank is spotless and attractive
  • It replenishes oxygen in the tank
  • It will make your fish happy


  • It is a method that requires a lot of effort to execute
  1. Utilize a water conditioner

Perhaps the easiest and most convenient way to remove ammonia from your tank after detecting it is to add an appropriate amount of a water conditioner. There are dozens of water conditioner brands and products that can remove ammonia from your aquarium very quickly and save your fish from death. You just need to choose a good product with positive reviews and you should be able to remove ammonia from your tank in double-quick time.

The best thing about using a good water conditioner to remove ammonia is that it will remove the toxic chemical alongside other chemicals such as nitrites (also toxic) and nitrates. The water conditioner will most likely do this by binding with the toxic chemicals and rendering them useless. When all the ammonia in your tank is bound, the chemical becomes inactive and loses its power and toxicity. This is what makes it useless.

The very best water conditioners can also be used to remove chlorine or chloramine from tap water before using the water to replace a percentage of your aquarium water. 

This means that when you buy a decent water conditioner, you should be able to use it to remove ammonia, nitrites, nitrates, and chlorine in double quick time without putting in much effort.


  • This method allows you to remove ammonia conveniently 
  • It allows you to do it quickly and save your fish and other critters
  • It is perfect for also removing other problematic chemicals from your tank
  • It is a method that does not require any effort


  • Since this method uses chemicals, it may affect the immunity of your fish


Ammonia is very hazardous to fish. It can poison your fish and cause stress, ill-health and even death to your fish. This is why it is important to detect it quickly and deal with it. There are two main ways you can use to detect the concentration of ammonia in your tank water – the use of an ammonia alert sensor or an ammonia test kit. If you use either of these two methods and find that the concentration of ammonia is high, you should use any of the four methods to get rid of the toxic chemicals. The methods include carrying out water changes and using a water conditioner.