Swordtail Fish Care Guide – Diet, Tank Mates & More

Swordtail Fish white background

The Swordtail is a very active fish that will undoubtedly bring you lots of joy as a pet over the years. 

If you have never kept fish before, this is an excellent one to start with. It is very docile by nature and can, therefore, get along with most other fish.

Swordtail Fish Appearance

Swordtails have a caudal fin with a tail that features an elongated lower lobe, making their appearance something special. They get their name from this sword-like protrusion. Keep in mind that only the males have this elongated tail lobe.

The average Swordtail grows to about 5.5 inches, though females tend to be slightly bigger. You’ll find that there are a number of variants that come in colors that include orange, red, and even black. 

The ones that are found in the wild are mostly dark green color with some crimson red on the side of their body.


One of the reasons that Swordtail fish are so popular is because they tend to get along very well with so many other species. Males can become aggressive when they are kept together. This is why it is crucial that you keep many more females than males in the same tank.

The Swordtail can get skittish around bolder fish, spending some of its time in seclusion. You’ll most likely find that they’ll eventually come out after a brief adjustment period. They tend to stay near the top of their aquarium or around the middle. 

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Swordtail Fish rare fish e1580477293285

Natural Habitat

The Swordtail fish can naturally be found in smaller rivers as well as streams. They prefer bodies of water where there aren’t many predators to contend with. These fish originally came from Mexico and all over Central America. They like to be in flowing waters as opposed to still bodies. You can also find them in certain parts of North America.

Swordtail Fish Care Guide

1. Tank Setup

Because Swordtails don’t spend much time at the bottom of their tanks, you won’t have to worry too much about the substrate. If you really want them to feel comfortable, sand makes for an excellent substrate material.

You also want to provide these fish will a decent number of rocks, caves and other things that they can hide away in. While Swordtails tend to spend a lot of time swimming around, they also need multiple places for seclusion when necessary. This will be sure to make them feel right at home in their home environment.

Make sure that you spread the plants across the tank so they are a good distance apart. Some of the best plants you can put in this fish’s aquarium include Dwarf Hairgrass and Anubias Nana.

2. Water Conditions

It is imperative that the water in your Swordtail’s tank has a pH of 7 to 8.4 and a hardness of 12 to 30 dgh. You’ll also want to keep the temperature of the water between 70 and 82 degrees Fahrenheit.

These fish are very sensitive to sudden changes in water temperature and quality, so you must keep that in mind. A pump is not necessary, as the filter outlet will most likely provide them with adequate water flow.

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You don’t want to keep Swordtails in a tank that is less than 15 gallons. If you are going to keep them with their own kind, you’ll need to tack on 5 to 6 gallons for every fish you put in. An adequate size tank is essential to keeping these fish happy and active on a daily basis.

3. Swordtail Fish Tank Mates

It shouldn’t be very difficult to find other fish to put in your Swordtail’s tank that they will get along with. Some of these fish include Mollies, the Pearl Danio, Neon Tetras, and angelfish. Zebra Loaches and Kuhli Loaches are two other good choices for Swordtail tank mates.

You’ll want to make a point of avoiding any fish that have a reputation for being aggressive, including Cichlids and Tiger Barbs.

If you want to keep things interesting, you should consider putting in a couple of shrimp or snails. This can shake things up in a good way.

Swordtail Fish in an aquarium

4. Swordtail Fish Food

Another thing that so many people like about Swordtail fish is that they can be fed a variety of foods. They eat up lots of vegetation, algae, and even insect larvae in the wild. 

If you get one of these fish while they are young, you need to make sure they get adequate protein. A good quality dried fish food is appropriate for this particular species.

You can feed these fish two or three times each day, but they don’t eat a ton. Make sure that you swim out any food that they do not eat with each meal so it does not impact the overall quality of their water.

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Once you have fed them several times, they will instinctually get increasingly active as mealtime approaches.

Common Health Problems

While Swordtail fish aren’t known for contracting diseases, it is certainly still a possibility. If you see any signs of illness with your fish, it is important that you keep them away from their tank mates. This will keep the disease under control so it doesn’t spread.


  • The elongated lobe on the tail of this fish gives it a truly unique look that many people find attractive.
  • While Swordtails are typically peaceful fish, they can become aggressive when kept with too many other males in the same tank.
  • If you are going to keep just one of these fish, you’ll need a tank that is at least 15 gallons.
  • Make sure that you add another 5 to 6 gallons for every additional Swordtail you put in the tank.
  • Swordtails get along with most other fish—Angelfish and Neon Tetras are just two good options to consider.
  • The diet of this fish should consist of a high-quality dried food that meets their nutritional requirements. 
  • These fish don’t usually contract serious diseases, but it’s still important to look for signs of illness in them.
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