Why Your Clownfish Is Laying On The Bottom?

Clownfish is one of the most fascinating and delightful species that attracts a lot of attention and people have actively started tank raising it in recent years. There is a lot to know regarding the living conditions of these creatures and scientists are constantly studying major causes of their behavior. If you are willing to raise a clownfish in the aquarium you may witness some strange habits and manners. One of them is that the clownfish might lay on the bottom of the tank all the time which can be quite confusing and concerning for newbies. We are here to provide thorough information regarding this subject and answer one of the most commonly asked questions – why your clownfish is laying on the bottom?

The clownfish laying on the bottom of the tank might be induced by some disease and poisoning or the parameters and water temperature of the aquarium being incorrect. Also, this kind of behavior is totally normal for some clownfish indicating no concrete motive, so you should not be worried. 

People often get frightened and confused seeing their playful and energetic clownfish suddenly starting to lay motionless on the bottom of the tank. Sometimes they do have a reason to feel nervous as the fish might have a deadly disease, but usually, it is a normal behavior characterizing a lot of fish species.

In this article, we will talk about the major purposes regarding this type of behavior that will help you to get more familiar with your clownfish. Let’s start!

Clownfish Laying on the Bottom – Main Reasons

As we have mentioned above, laying on the bottom of the aquarium can be induced by different reasons. Although the majority of these reasons are harmless, we encourage the owners of clownfish to take this case seriously. It might be some poisoning or disease causing the fish to stay immobile and may end up dead if you don’t pay attention timely.

The main disease representing a lot of fish species is a swim bladder disease which is not treatable in most cases. As for the poisoning, we want to point out two major reasons – Ammonia poisoning and Nitrate poisoning. There are also other stress-related issues which we will mention below.

Usually, it is normal for clownfish as well as other species to stay at the bottom of the tank frequently. Maybe it is the place they find most comfortable to rest and sleep at night. Therefore, there is nothing to be worried about as long as they don’t show any signs of illness.

Another reason might be related to the size of your aquarium and the water temperature inside it. If your aquarium is too small and the temperature of the water is too hot the clownfish will most likely find the bottom of the tank the most pleasant place to stay.

Clownfish Is Laying On The Bottom
Clownfish Is Laying On The Bottom

So, we would like to wrap up the reasons behind this kind of behavior of clownfish as a list so that you will have a better understanding of it. Our list includes –

  • Swim Bladder Disease
  • Ammonia Poisoning
  • Nitrate Poisoning
  • Aquarium Size
  • Water Temperature
  • Rest
  • Sleep

These are major reasons inducing clownfish to lay on the bottom of the tank and in the next part of this article, we will discuss them one by one and you will get a proper understanding of this behavior.

How Did Your Clownfish get Swim Bladder Disease?

As we have noted above, a swim bladder disease is an extremely common illness among the majority of fish species. The swim bladder is a key organ of every fish as they swim with the help of it.

This disease causes a condition when the bladder is damaged and it is not functioning any longer. As a result, your clownfish may start to swim in strange patterns until it’s not capable of moving anymore and finally lay at the bottom of the tank.

The swim bladder disease is often caused by overfeeding the fish especially when they lack the ability to digest food properly. In this case, you should reduce providing meals for a few days and feed it with food rich in fiber.

Sometimes, different abdominal organs could get enlarged due to other diseases causing swim bladder disorder. Antibiotic treatment could be beneficial if the source of problem is parasites or bacterial. Usually, this disease is chronic and the treatment is meaningless. So, you should be ready to euthanize your clownfish. 

What Are The Signs Of Ammonia Poisoning In Clownfish?

If you find your clownfish breathing heavily and refusing to eat while laying at the bottom of the tank then it’s time to check for ammonia poisoning. Ammonia is a very dangerous chemical for fish as it may damage the gills and lead to death.

The main issue is that you can’t see ammonia. You should check the level by using an aquarium test kit and if it shows high numbers then it’s time to take some actions.

Clownfish laying on bottom
Why clownfish is laying on bottom?

In this case, you should start changing the water regularly. Our suggestion would be to take out approximately 25% of water and repeat this process for a few days. Once you notice that the chemical levels are balanced you can stop changing the water and start cycling your aquarium with good filters.

What Happens When There Is Too Much Nitrate Poisoning In The Tank?

Like ammonia, nitrate is also another produced by fish waste. Generally, the symptoms are the same in both cases as they are caused by a chemical spike that causes trouble with breathing.

Nitrate is a relatively slow killer compared to ammonia and it might make the fish lethargic. As a result, your clownfish will most likely start laying on the bottom of the tank.

You should use a test kit in this case also to check the nitrate levels. If it shows a high number then you should start performing water changes regularly and it will be a good idea to add a cycled filter to your tank as well.

You must remember that the nitrate level should not exceed 20 ppm! It should be somewhere between 5-10 ppm.

If you are interested in learning more about your fish behavior, check out the links below:

Can A Clownfish Live In A small 1-Gallon tank?

The majority of people especially newbies don’t realize how important is the size of the aquarium. Some kinds of species are not capable of living everywhere and you should take into mind the space required for specific fish. This applies to clownfish as well.

1-gallon tank is not recommended to keep your Clownfish for long. A 10-gallon tank will be perfect to keep only one Clownfish, but Ocellaris Clownfish may need at least 20-gallon tank. A pair of Clownfish may require 20-gallon tank or more in general.

They are energetic individuals who love to swim around constantly and if you contain them in a small tank with hardly ever space, they will get bored and might bury themselves at the bottom of the aquarium.

If you are just starting to get familiar with these creatures, it’s important to remember this statement. The bigger aquarium equipped with some plants and decorations ensures comfort and happiness for your clownfish.

Can A Clownfish Live In A Cold Water?

It is extremely important for the health of your clownfish to keep the water condition stable in your aquarium. It’s because the amount of oxygen mainly depends on the water temperature in the tank.

The warm water is not able to maintain as much oxygen as cold water. Therefore, it’s advised not to keep the water hot in your aquarium otherwise the clownfish will seek the cold place at the bottom of the tank. Keep the water temperature in the range of 72-78 deg F.

According to several studies, warm water also increases the metabolism of fish which may end up with fatal results. Therefore, try to slowly cool down the temperature of your aquarium using an air conditioner or fan.

Additionally, we suggest not to make the water too cold as well because it has some negative outcomes as well. Try to keep it stable and your clownfish will happily reside in the tank.

Is Your Clownfish Resting or Dying?

We have already noted above, that most of the time this type of behavior is quite normal for many species of fish. The clownfish is not an exception as well. Like every living creature, the fish requires some rest too and sometimes they find the bottom of the aquarium the most comfortable place to lay.

Clownfish laying at bottom
Clownfish at bottom of fish tank

Therefore, if your clownfish is not showing any sign of disease and the aquarium conditions are fine you should not be worried. We can see a lot of questions asked by rookies regarding this topic as they get pretty nervous and confused. We would like to inform everyone that your clownfish is laying on the bottom of the tank simply to relax.

Does Clownfish Ever Sleep?

As for every living individual, sleeping is very important for fish also. They need to sleep well at night to get energy for the day and therefore it is one of the most common reasons for them to lay on the bottom.

When the tank lights are off clownfish often dive on the bottom to rest and sleep at night. Leaving the lights on can cause some difficulties for the fish. If they can’t get enough sleep at night, you might see them snoozing at the bottom of the aquarium during the day.

This is another reason indicating that your clownfish is completely fine and it is just showing this behavior for understandable purposes.


In this article, we have touched on one of the most concerning topics for every clownfish owner. Clownfish may display some strange behaviors from time to time and you may find it laying on the bottom of the tank frequently.

There are several reasons behind this behavior and we have explained every one of them in detail. If you came here frightened because of this behavior, we hope we were able to inform you thoroughly and help you to solve this issue.

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