9 Ways to Lower Ammonia Level in Aquarium and Get Rid of it

Ammonia is very harmful to your fish.

It is the most common cause of death of a fish in the aquarium.

If you notice a high ammonia level in your aquarium then you should immediately do some measures to reduce it.

In this article, I am going to share with you some ways to lower the ammonia level in your aquarium and ultimately get rid of it.

Ways to Lower Ammonia in Aquarium

ways to lower ammonia in aquarium

1. Partial Water Change

When you notice ammonia in your aquarium then the simplest and easiest way to lower ammonia immediately is to do a partial water change.

You should do a water change of about 30 to 50% of the total water in your aquarium.

The freshly introduced water will not have ammonia so it will help to dilute the ammonia in your aquarium.

How to do a partial water change

  • First of all, you should take a clean bucket which you have never used with any chemical or soap. If you are in doubt then buy a new bucket and keep it aside for aquarium maintenance only. Then pour normal tap water into the bucket.
  • Before introducing the tap water into the aquarium you need to dechlorinate it. There are two ways to dechlorinate water. The first way is to let the water seat overnight. But if you are in emergency then you should use a dechlorinating agent that you can easily find at your nearest pet shop. Check out our recommended Dechlorinating Agent
  • Once you dechlorinated the water then switch off all the electrical supply to the aquarium i.e switch off the light and the filter.
  • Then remove about 30 to 50% of the water from your aquarium using a hose. You can also use a siphon to do so, it really makes it easier to remove water from the aquarium. Check out our recommended Vaccum Cleaner or Siphon
  • Now slowly introduced the freshwater into the aquarium.

2. Cycle Your Tank

If you have a new tank then the chances are there are very low beneficial bacteria in your aquarium.

The beneficial bacteria, as the name suggests, are the bacteria that are good for your tank and that actually helps to reduce the ammonia in your aquarium.

To increase the beneficial bacteria in your aquarium you need to cycle your aquarium.

3. Improve the Filtration

Weak filtration can also cause a rise in the ammonia level in your aquarium.

There are several things you can do to improve filtration in your aquarium.

Use a filter

If you are not already using a filter then you should definitely use a filter for your aquarium.

The filter not only keeps the water clear but it also provides a place for the growth of the beneficial bacteria that helps to reduce the ammonia level in your aquarium.

If you have a small tank about 20 gallon then a hang on the back filter is sufficient for you.

If you have a larger tank then you should go for a canister filter.

Add another filter

If you are already using a filter for aquarium then to improve the filtration you should add another filter in your aquarium.

For example, if you have a large tank and you are using a canister filter for it then you should supplement it with another hang on the back filter.

Unclog the filter

If you notice the water from your filter is not flowing freely then you should clean the filter.

But here you should be careful while cleaning the filter because if you clean the filter wrong way, it can cause loss of all the beneficial bacteria in the filter.

So you should clean your filter using the aquarium water. This way the beneficial bacteria will be preserved.

Remove unnecessary impurities

Unnecessary impurities like uneaten food, dead plant, and fish cause a high ammonia level in the aquarium.

So you should remove such impurities from the water using a fishnet.

If you found a lot of uneaten food in your aquarium then you should cut down on the quantity of the food you feed to your fish.

Vacuum your substrate

There will be a lot of impurities trapped in the substrate in your aquarium.

This impurity can cause a rise in the ammonia level of your aquarium.

So you should clean your substrate regularly using a siphon.

Lower the pH of the water

Lowering the pH of the water not necessarily remove the ammonia from the water but it makes it less dangerous and gives you sufficient time to fix the problem.

If you are using substrate like crushed coral or coral sand then this could be the reason your aquarium water has high pH because it releases calcium that causes a spike in the pH level of the water.

How to lower the pH of the water

  • In an emergency, you can do a partial water change to lower the pH of the water.
  • You can use driftwood which is specially made for aquariums to lower the pH of the water. The driftwood releases tannic acid that helps to lower the pH of the aquarium. While buying the driftwood for the aquarium just make sure that it is not treated with any chemicals or dyes.
  • Another simple way to lower the pH of the water is by introducing some almond leaves in the aquarium. It works the same way as the driftwood. It will release tannic acid that helps to reduce the pH of the water.

4. Increase Aeration in the Tank.

Increasing aeration in the tank can help to lower the ammonia level in your aquarium.

The ammonia gas in the NH3 form is toxic for your fish and it can dissolve in the water.

So, if you increase the aeration in your aquarium then it can get out of the water and into the air.

How to increase aeration in the water

  • The simplest and most reliable way to increase aeration in the water is by using an air pump. Check out our recommended Air Pump
  • You can also use a hang on the back filter to increase aeration.
  • You can use a spray bar to increase aeration in your aquarium.

While you are aerating the tank just make sure that it is not covered with a lid.

5. Upgrade to a Bigger Tank

If you have a lot of fish in a relatively small aquarium then this could be the reason your tank has high ammonia levels.

In this case, you should upgrade to a bigger tank that will help to dilute the ammonia in the tank.

If there are a lot of fish in a small tank then the fish will produce a lot of waste that will ultimately produce ammonia and as the fish tank is small the water will get concentrated with the ammonia.

So upgrading to a bigger tank can help to dilute the ammonia.

6. Keep Live Plants in the Aquarium

Keeping live plants in the aquarium is a very good way to reduce ammonia in the aquarium.

The live plants require macronutrients and micronutrients for their proper growth which they can get from waste produced by fish and uneaten food.

So, if the reason for a rise in the ammonia level in your aquarium is the uneaten food and waste produced by your fish then the plant will absorb it and use it as a fertilizer for their growth. 

Also, plants will release oxygen which is actually beneficial for the fish.

If you are a beginner then you should start out with some Hardy plants like Anubias, Java fern, Java Moss, etc.

7. Add Beneficial Bacteria

If your fish tank is new then the chances are your aquarium has high ammonia is because you are fish tank has low beneficial bacteria.

So in this case, to increase the beneficial bacteria instantly you should add some gravel from the established aquarium into your aquarium.

The gravel is a place where beneficial bacteria live so when you add the gravel from an established fish tank in your aquarium then you are basically adding beneficial bacteria in your aquarium.

You can also use a filter pad of a filter which is used for the filtration of an established fish tank and use it into your own filter.

You can get this filter pad or gravel from your friend or from your nearest pet shop.

Just make sure that when you get the gravel or the filter pad, put it inside the aquarium water so that the beneficial bacteria will not die.

8. Preserve the Beneficial Bacteria

The ammonia level in your aquarium may have raised because you have accidentally removed the beneficial bacteria from your aquarium.

If you are using a substrate like gravel for your aquarium then this is the place where the beneficial bacteria colonize.

Also, beneficial bacteria grow into the filter of your aquarium.

Usually, when you clean your substrate like gravel and filter with normal tap water you lose all the beneficial bacteria.

So, you should not clean your gravel or subtract with normal tap water. Instead, you should clean it using your aquarium water.

This way, your beneficial bacteria will be preserved.

9. Use Neutralizing Drops

The temporary way of reducing ammonia in your aquarium is by adding some neutralizing drops into your aquarium.

The neutralizing drops, not necessarily remove the ammonia from your aquarium but instead, it makes ammonia harmless.

You will still need biological filtration to get rid of ammonia completely.

What are the causes of ammonia in a fish tank

Unnecessary waste

Unnecessary waste like dead plants, dead fish, uneaten food produces ammonia.

So you should regularly check your aquarium and if you found anything like that then you should remove it using a fishnet.

Also, there is some unnecessary waste trapped into your gravel like the decade plant roots.

To remove it from the aquarium you should vacuum your gravel using a siphon.

How frequently you will have to use the siphon is really depends on how much unnecessary waste gets trapped in your aquarium.

Generally, you should clean your gravel once in two weeks.

Overstocking

This is a very common reason that causes a high ammonia level in your aquarium.

When you put a lot of fish in a relatively small tank, the fish produce a lot of waste that causes high ammonia in the fish tank.

So upgrading to a bigger tank or removing some fish from the aquarium will easily solve the problem.

Besides, you can also do some other things to increase the beneficial bacteria in your aquarium so that the bacteria will reduce the ammonia from the water.

Ways to increase beneficial bacteria in the aquarium

  • Add another filter– aquarium filter not only filters the water in your aquarium but it also provides a place for the growth of beneficial bacteria. So adding another filter in your aquarium can help to increase the beneficial bacteria in your aquarium.
  • Add some gravel– if your aquarium doesn’t have any substrate then adding some gravel can help to increase the beneficial bacteria. Because gravel will provide space for the colonization of the beneficial bacteria.
  • Keep live plants– keeping live plants in the aquarium is a great way to lower ammonia. Plants will use the ammonia in the aquarium as a fertilizer for their growth and it will also release oxygen which is beneficial for the fish. Besides, plants also provide a place for the colonization of beneficial bacteria.

Bad filtration

Bad filtration can also cause a high ammonia level in your aquarium.

As mentioned above, aquarium filters not only filter the aquarium water but also provide a place for the growth of the beneficial bacteria.

So, if you notice the water from the filter is not coming out freely then you should clean the filter using best practices.

Also, you can supplement your aquarium with another filter to increase the beneficial bacteria.

Low amount of beneficial bacteria

This is also the most common reason aquarium has a high ammonia level.

Beneficial bacteria is the bacteria that helps to remove ammonia from the aquarium.

And obviously, if you have less beneficial bacteria in your aquarium then the ammonia level will rise.

High water PH

High water pH can also cause a high ammonia level in your aquarium.

So, in this case, lowering the pH of the water can solve the issue.

Usually, when you use coral sand or crushed coral substrate, it produces calcium that causes high PH in the water of the aquarium.

Not cycling the aquarium

This is the mistake most beginners make when they are just starting out with the hobby.

You need to cycle the aquarium before you even put the fish into the aquarium.

Cycling the aquarium basically helps to create the beneficial bacteria in your aquarium. 

So when you put your fish into the aquarium your tank will be ready to remove the ammonia from the aquarium that your fish is going to produce through its waste.

What are the symptoms of ammonia in the fish tank

Lethargy

If you noticed your fish is moving around less then this could be the reason your aquarium has high ammonia levels.

But you should not get confused with a sleeping fish.

Fish usually sleep near the bottom of the tank hovering over the water.

The fish don’t have eyelids so their eyes are open while they are sleeping.

Loss of appetite

If you notice your fish is eating less then it used to eat then this suggests a high ammonia level in your aquarium.

Gasping at the surface

It is very common for some fish to come on the surface but if you notice your fish is coming on the surface very frequently then this could be because your aquarium has a high ammonia level.

When fish come on the surface of the tank gasping for air it also suggests low oxygen in the aquarium.

And there are several ways to cope with this issue.

Inflamed gills

If you notice swollen gills of your fish, it is a sign that your aquarium has high ammonia.

Red streaks or inflammation in the fins

If you noticed red streaks or swollen fin of your fish then this could be because your aquarium has a high ammonia level.

Inflamed eyes or anus

High ammonia level also causes inflamed eyes or anus so if you notice such things in your fish then your aquarium has high ammonia.

Conclusion

I hope you will find these ways to reduce ammonia helpful. Ammonia is very harmful to your fish so you should regularly check it

Also, ammonia levels can rise quickly so before doing any permanent solution that may take time, you should do a partial water change or use neutralizing drops for the time being.

FAQ

What is the acceptable ammonia level in a freshwater aquarium?

Ideally, your aquarium should not contain any ammonia. But if you noticed more than 1 PPM ammonia in your aquarium then you should look for ways to reduce it because it can be harmful to your fish.

How to check ammonia levels in a fish tank?

The simplest way to check the ammonia in your aquarium by using an ammonia test kit. Check out our recommended Test Kit

Is 0.25 ammonia safe for fish?

As mentioned above, ideally your fish tank should not contain any ammonia.
But 0.25 ammonia level is not harmful to your fish and it will not cause the death of your fish.
If the ammonia rises more than 0.50 PPM then you should look for ways to reduce it.
If the ammonia level rises more than 0.50 PPM then it would be very harmful to your fish and it can even cause death.

Can a fish recover from ammonia poisoning?

Currently, there is no way available to cure a fish of ammonia poisoning.
But you can prevent ammonia poisoning by cycling the tank before introducing fish into it.
There are also some other ways (as mentioned above) to reduce ammonia in your aquarium before it can harm your fish.

What level of ammonia is toxic to marine fish?

Ideally, your Marine tank should not contain any ammonia.
But if your tank has ammonia in small quantities then it will not cause any harm to your fish in the short term.
But in the long term, if your tank has very little ammonia of even 0.02 PPM it can cause harm to your fish over time.
So, you should regularly check the ammonia level in your Marine tank.
And you should take some action to reduce the ammonia if you noticed any ammonia in your Marine tank.

Do snails reduce ammonia?

Snails don’t help to reduce ammonia in your tank.
Snails actually produce ammonia in your tank.

Why it is important to reduce ammonia in your aquarium?

Ammonia in the aquarium water can cause ammonia poisoning in fish.
When fish take ammonia-rich water through their mouth and release it through their gills it hurt their gills.
Basically causes tissue damage in the fish which makes it harder for fish to respire.

Why does ammonia is harmful to fish?

When dissolved in surface water, ammonia exists in two forms: NH30 (unionized) and NH4+ (ionized).  Ionized ammonia does not easily cross fish gills and is less bioavailable than the unionized form (Francis-Floyd 2009; EPA 1989).  The unionized form (NH30) can cross from water into fish, and once inside, some converts to the ionized form (NH4+), which then causes cellular damage (EPA 1989). (source)

Is ammonia bad for aquarium plants?

Ammonia is actually good for plants and they use it as a nitrogen source and then nitrite and nitrate source.
But excess ammonia can harm the plants.

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Author
Prathmesh Gawai
He is the main author and editor at Aquagoodness.com. And he loves to share helpful information on aquarium and/or fishkeeping hobby. Prathmesh has over five years of aquarium and/or fishkeeping experience. Currently, he has a Betta fish tank. He has written hundreds of articles on various aquarium fish species and on fish tank maintenance over the last five years. Connect with him on YouTube here. Learn more about him here.

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