Why Is My Swordtail Laying at the Bottom of the Tank?

Why Is My Swordtail Laying at the Bottom of the Tank?

The swordtail fish is one of the most popular freshwater fish sold. They have a distinct appearance and character, which is why they’ve become so popular.

However, there may be times when your swordtail starts to act strange, like lying at the bottom of the tank. So,  why is my swordtail lying at the bottom of the tank?

There are a few reasons why your swordtail may be lying at the bottom of the tank. The most common reason is that they’re sick or injured.

Swordtails are very sensitive to changes in water quality and temperature, so even a small change can make them sick.

In this article,  we’ll discuss the most common reasons why your swordtail is lying at the bottom of the tank and what you can do to help them.

Do Swordtails Usually Lay at The Bottom?

No. Most swordtails do not lay at the bottom of their tank. They prefer to swim in the middle or top sections of the aquarium, rather than at the bottom.

If you notice your swordtail fish at the bottom of the aquarium, there is something wrong with it.

There are some cases where a swordtail may lay at the bottom for short periods of time. For example, if they’re resting or sleeping, they may sink to the bottom of the tank.

However, if you see your swordtail at the bottom for a long time,  it’s probably something serious.

Why Is My Swordtail Lying at The Bottom of The Tank & How to Prevent It?

There are several reasons why your swordtail might be found at the bottom of the tank. They may be pregnant or nursing live fry, which can cause them to lay on their sides.

Another possible reason for a lying down posture could be that they are stressed. If they have too much stress, some of them might lay at the bottom of their tank.

The following are just a few of the most common reasons:


If you see your female swordtail lying at the bottom of the tank, she may be pregnant or in labor.

Swordtails are livebearers, which means they give birth to live fry. A female swordtail can carry anywhere from 20 to 60 eggs at a time.

As the fry develops, they will start to put pressure on the mother’s sides. This can cause her to feel uncomfortable and want to lie down at the bottom of the tank.

How will you know that your pet is pregnant?

  • They prefer to stay alone and under limited motions.
  • The fish will show a swollen belly and dark spots.
  • It becomes inactive, territorial, and may go without food.

Poor Tank Conditions

One of the reasons your swordtail is lying at the bottom of the tank is because of poor water quality.

Swordtails are very sensitive to changes in their environment. So, even a small change in water quality can make them sick.

You need to check your water quality regularly and make sure it’s stable. The following are some of the things you need to check:

  • Water changes: You must change 25% of the tank’s water every week, and you must keep an eye on it.
  • Tank size: The smallest size for a swordtail fish is 15 gallons. If you need to raise more swordtails in the same tank, you’ll need tanks with capacities of up to 30 gallons. This guarantees extra room for convenient movement within the aquarium.
  • pH levels: It’s also important to keep the pH at 6.8-8 by monitoring it regularly.
  • Water temperature: Ideal temperatures should vary between 72 and 78 degrees Fahrenheit.
  • Water hardness: The water hardness should be between 1DH and 24DH.

Diseases and Parasites

There are a few diseases that can make your swordtail sick, such as:

  • Fin rot: This is a common disease that affects much fish. It’s caused by bacteria and it can eat away at your fish’s fins and tail.
  • Dropsy: This is a disease that affects the internal organs of the fish. It’s caused by a build-up of toxins in the body, and it can be fatal.
  • Ich:  This is a common disease that’s caused by parasites. It can cause your fish to itch and scratch, and it can be fatal if left untreated.
  • Gill flukes: These are parasites that attach themselves to the gills of the fish and cause respiratory problems.

The most effective approach to prevent it is by establishing a suitable climate and providing your pet with a well-balanced diet.

Unsuitable Tank Mates

Another cause of your swordtail’s sinking to the bottom of the tank is that they don’t get along with their tankmates, or you may not have any other fish in there with them.

They may be frightened by bigger and more violent species that need to fight back, making them a target for abuse.

Because of this, to avoid being bullied, they usually erect their boundaries at the bottom of the aquarium due to the presence of hiding-outs.

To solve this problem, you need to constantly monitor the pets in the tank and identify the bully. After that, relocate aggressive bullies to another aquarium.

Lack of a Hiding Place

Another reason your swordtail is at the bottom of the tank is that it doesn’t have a hiding place.

Swordtails are very shy fish, and they need a lot of places to hide. If they don’t have anywhere to hide, they will be stressed, and this can lead to diseases.

To fix this, you can add more plants and décor to the tank. This will give your swordtail plenty of places to hide.

Ammonia Poisoning

One of the main causes of your swordtail sinking to the bottom of the tank is ammonia poisoning.

Ammonia poisoning occurs when the levels of ammonia in the water rise to a toxic level. This can happen for a variety of reasons, such as overfeeding, not changing the water often enough, or having too many fish in the tank.

If you think your fish might be suffering from ammonia poisoning, you should do a water test to check the levels of ammonia in the water. If they’re high, you’ll need to do a water change immediately.

Do Swordtails Sleep at the Bottom?

Yes, swordtails sleeping at the bottom of the tank may appear odd, but it isn’t unusual.

Swordtail fish can’t sleep as humans do, but when it’s time for them to rest, they’ll lay at the bottom of their aquarium for a bit.

Last Words

Now that you know the reasons for your swordtail sinking to the bottom of the tank, you can take steps to fix the problem.

Most of the time, the problem is easily fixable and won’t require any major changes to your aquarium.

However, if you’re concerned about your fish’s health, you should always take it to the vet for a check-up.

We hope you enjoyed reading this article and that it helped answer your question. If you have any further questions or concerns, please don’t hesitate to reach out to

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