Swordtail Fish

The Ultimate Swordtail Care Guide for Beginners

If you are like most aquarists, you may be looking for an attractive, easy-to-care-for fish to add to your tank.

Swordtails may be the perfect choice for you! These fish are hardy and come in a variety of colors, making them a popular choice for both beginner and experienced aquarists alike.

In this guide, we will discuss the proper care for swordtails and provide tips on how to create the best environment for them.

So without further ado, let’s jump into details.

Swordtail Fish Origin

Swordtail fish are native to freshwater rivers and streams of Mexico.

It is found in the waters of southeastern parts of the U.S, north of the Rio Grande River in Texas.

It is also found in Guatemala, El Salvador, and Honduras.

Swordtail Appearance

The most distinctive feature is the male swordtail fish’s caudal fin is.

The lower lobe is elongated, forming a sword-like protrusion that can be as long as the rest of the body.

Females, on the other hand, do not have that extra lobe, so, it’s simple to tell them apart for breeding purposes.

In terms of overall shape, swordtail fish have a rather typical build.

They have a streamlined body, wide tailfin, pointed snout, and downturned mouth.

Color, on the other hand, offers a plethora of options!

The majority of wild specimens have an olive green base with a brown lateral stripe that runs through the blade.

However, cross-breeding has given fishkeepers all kinds of distinct visual possibilities.

Red, orange, and black are some of the most popular morphs.

Further, there are multi-colored swordtail fish and unique variants with distinctive designs exist as well.

Typical Behavior

Swordtail fish are one of the easiest freshwater fish to keep since they get along well with others in their tank, and if you met their water requirements and feeding demands, they will be a great addition to your community tank.

Even though these species aren’t schooling fish, keeping them in a group of 5-6 will help them feel more at ease in the aquarium.

The male swordtail fish can also become territorial, so avoid keeping too many males in the same aquarium and make sure that they’re outnumbered by females four to one.

Furthermore, they stay in the center and upper levels of the tank while rarely going down to the bottom.

And if they have enough swimming room, they will be very active residents of your aquarium.


When we talk about longevity, we must understand that the lifespan of a swordfish and any other fish is determined by their living conditions and the food they are given.

The level of care you give your beloved fish has a big impact on their health and their lifespan.

Genetic predisposition and illnesses, on the other hand, can reduce their lifespans and reduce the amount of time you can enjoy these lovely creatures.

In general, the typical swordtail fish lives for between three and five years.

Average Size

Despite the males having a longer tail, the females are bigger and can reach up to 6.5 inches in length, whereas the male ones reach 5 to 5.5 inches in length.

Water Parameters

Although swordtail fish aren’t picky about the tank environment and they can survive in a wide range of water temperatures.

However, they still have a preferred temperature and pH level that makes them feel more at comfort and healthy.

1. Water Change

As we mentioned, swordtail fish is not particularly demanding about water changes.

However, a regular routine of 10% per week is recommended to keep [ them away from disease.

2. Water Temperature

Swordtail fish are tropical fish that live in warmer environments.

For this reason, if you’re keeping swordtail fish in your tank, you should provide them with the conditions they would experience in nature.

The temperature in the regions where these species live ranges from 77 to 82 degrees Fahrenheit, owing to the fact that tropical areas receive more sunlight exposure.

This is the ideal temperature for the majority of freshwater fish species, which explains why swordtails can coexist with so many other species.

As a result, the ideal water temperature for swordtail fish is between 77 and 82 degrees Fahrenheit.

However, because swordfish are robust animals, they can survive temperatures as low as 65 degrees Fahrenheit.

3. pH Level

As we mentioned before, swordtails are resilient and can endure a wide range of temperatures, hardness, or water pH levels.

However, low or high water pH levels can have a detrimental impact on your swordtail fish, resulting in illnesses, stress, poor resistance, and even death.

Alkaline water is preferable for these species; therefore the appropriate water pH for a swordtail should be between 7.0 and 8.4.

Tank Setup

1. Tank Size

Swordtail fish are small, and they don’t require much space since to their size.

Regardless, because they are very active, they will greatly benefit from having enough area to swim about.

The suggested swordtail tank volume is 15-20 gallons.

However, as we’ve stated before, the larger the better, and though they are not formal schooling fish, they do move in groups for comfort and security, especially in community tanks.

So raising them in a small tank would put them under stress which will lead to illness in dangerous situations.

Therefore, if you’re keeping a bigger group of swordtail fish together, we recommend using a 30-gallon aquarium to give each one enough room to swim around freely while still providing maximum comfort

2. Tank Heater

As we stated before, swordtail fish can tolerant a long range of water temperatures.

However, if you live in cold temperatures, then swordtail fish need a heater in the aquarium to survive

A heater will maintain a consistent water temperature in your fish tank so that your fish can live comfortably.

3. Tank Filter

Swordtail fish can live without a filter. However, they would benefit from the use of one.

Swordtails generate a large number of pollutants.

The amount of ammonia and nitrite will be increased as a consequence of these emissions.

Without filters and live plants, the ammonia spike will soon intoxicate your swordtail.

If you don’t want to use a filter, you’ll have to do frequent, high-volume water changes every day.

You must also monitor the water quality on a daily basis.

It’s too much work, right?

For this reason, we recommend employing a filter to make your job ten times easier.

4. Tank Lighting

Have you heard of the circadian rhythm? It’s a term that means “daily routine.”

So, the circadian rhythm is a 24-hour cycle that affects various activities in animals.

It’s also known as the “daily rhythm” and helps the fish figure out when to go to sleep and wake up by relying on the light.

Finding that equilibrium between exposing them to sunlight for their health and allowing them to rest or sleep by shutting off the lights at night might be difficult.

Based on our experience, a lighting schedule of 8-10 hours daily is more than sufficient for your swordtail fish.

However, excessive light exposure can be harmful and may also result in death.

If you want to ensure that your swordfish gets the appropriate amount of illumination, consider investing in a timer that will turn off the lights after they’ve been on for several hours.

Also, if it’s dark enough outside at night and you’d want something soothing to look at while sleeping, you could use a “moonlight” or low-intensity night light.

5. Tank Decoration

Swordtail fish prefer heavily vegetated areas in which they evolved in the wild.

As a result, while you want to replicate those circumstances in your home aquarium, you don’t want to go too far.

Your first priority should be the natural biotope before anything else.

When it comes to decorating a tank for a swordfish, the type of plants and their positioning must be particularly meticulous.

Always include plants that are natural friends and those that will help them hide when they need to.

And since they aren’t bottom feeders, you don’t have to worry about the substrate much.

You just need to pay attention to the plants you want.

Stick to natural plants rather than fake plastic ones. Some of the greatest aquarium plants include:

  • Java fern
  • Anubias
  • Dwarf hairgrass

These plants allow them to conceal themselves when they need to, and provide enough hiding places for the fish to swim freely without discomfort in the tank.

Also, if you’re adding plants, make sure a covered tank lid is installed because swordtail fish are jumpers and will attempt to leap out of the tank.

Tank Mates

Swordtails dislike being alone. They spend the majority of their time exploring the tank and enjoy good company.

As a result, it would be wrong to keep your swordtail alone.

This can lead to a lot of issues, including loneliness, stress, and weakness.

Therefore, you must have other fish friends to keep the swordfish company.

When it comes to choosing the right company for your fish, they must match your beloved sword tails’ water parameters, size, behavior, and temperament.

Since these fish are small and peaceful fish, then they will enjoy the company of fish that show similar characters.

Larger and aggressive fish, on the other hand, will try to attack them and make them stressed and uncomfortable.

So, keeping such fish with swordtails is not a very good idea.

Because of such factors, matching compatibility is critical.

Some of swordtail fish best tank mates:

  • Common Pleco (Pterygoplichthys pardalis)
  •  Angelfish (Pterophyllum scalare)
  • Betta (Betta splendens)
  • Black Molly (Poecilia sphenops)
  • Neon Tetra (Paracheirodon axelrodi)
  • Madagascar Rainbowfish (Bedotia geayi)
  • Zebra Danio (Brachydanio rerio)

Diet and Feeding

Swordtail fish are natural omnivores who eat almost anything they come across in the wild.

Bug larvae, plant waste, and tiny microorganisms are typically on the menu for this fish.

In an aquarium, Swordtail fish prefer a diet comprised of commercial food and special high-protein snacks.

therefore, it is important to stick with nutritious flakes or pellets.

Also, every now and then, offer algal wafers to provide some plant-based food.

Brine shrimp, daphnia, bloodworms, and other high-protein treats all work as well.

Just put in your mind that juveniles should have a higher protein content than usual to develop properly.

How often should you feed them?

Two or three small meals each day are recommended for both adults and children.

During each feeding, give your fish enough to eat in two minutes.

If there are any leftovers, sieve them out to prevent the water from becoming unsuitable.


Just like other livebearers, it’s easy to breed a swordtail fish.

They’re quick to reproduce in captivity, In the appropriate condition, females can give birth once every 28 days!

While they will produce eggs in your main tank without you doing anything, it’s recommended that you provide a separate breeding aquarium.

The creation of a breeding tank improves the fry’s chances of survival.

Also, there are some steps you need to follow to encourage your beloved fish to put the babies.

First, raise the breeding tank temperatures to around 80 degrees gradually.

Then, provide your fish with several fine-leaf plants throughout the aquarium so that the larvae have somewhere to hide.

Finally, maintain good water quality and provide your breeding pair with high-protein meals for optimum results.

When they’re ready, the fish will lay their eggs.

Pregnant females generally congregate in one corner of the tank and remain there until they give birth.

It’s important to note that you should remove the fry after the female has given birth.

These fish have no parental instincts and will attempt to consume their young as soon as they are born.

What to feed the fry?

The fry are too little to consume regular flakes or pellets.

As a result, you must offer powdered fish food, infusoria, or freshly hatched brine shrimp.

Feed the fish until they are big enough to eat normal meals.


Despite swordtail fish being hardy, they aren’t immune to the typical ailments that most freshwater species face.

If you detect any indications of excessive aggressiveness or consistent lethargy in the fish, it’s an indication of disease.

A swollen abdomen is sometimes a typical symptom of an infection.

In situations like these, you should act fast and remove the afflicted fish from the tank to avoid spreading the illness throughout the remaining fish in the tank.

There are the two most common diseases for swordtail fish:


Ich, or white spot disease, is one of the most prevalent types of parasitic infections that they acquire.

These are due to external parasites in the tank water and can be prevented by frequent water cleaning and maintenance.

The ideal treatment for Ich is to raise the temperature of the tank water to 82 degrees Fahrenheit before adding one teaspoon of salt per gallon of water.

Mouth Fungus

Other than Ich, these little freshwater fish can also be afflicted with cottonmouth or mouth fungus, both of which are viral diseases.

This illness causes the fins and tails of the fish to grow uncontrollably fluffy.

To stop this disease from spreading, you’ll need to give them an antibiotic treatment.

Last Words

 If you’re looking for a fish that is both beautiful and easy to care for, swordtails may be the perfect choice for you.

With a little bit of knowledge about their needs and some basic supplies, you can create a healthy and happy home for your new swordtail friends.

We hope you enjoyed this article as much as we did.

If you still have any questions, please share them with us in the comment section below.