Swordtail
Xiphophorus hellerii
Also known as Green Swordtail
Edited by Ivan F. · Reviewed
Beginner verdict
A larger, active livebearer whose males grow a long sword on the tail. It needs much more room than a platy, and males can form squabbling pecking orders in small tanks. Give it a long tank, more females than males, and hard water for good health.
Care at a glance
- Min tank size
- 29 US gal
- Footprint
- 47 x 12 in
- Temperature
- 61–82 °F
- pH
- 7–8
- Hardness
- 10–25 dGH
- Swim zone
- Top
- Min group
- 3 fish
- Lifespan
- 3–5 years
Swordtail care mistakes to avoid
The mistakes beginners most often make with this species.
- Do not buy just one or two. Keep at least 3 fish so they feel secure.
- Plan for a long tank. Swordtails are active and larger than many beginners expect.
- Keep more females than males. Males in tight spaces waste energy fighting for rank.
- Use a lid, because this lively fish is known to jump.
- Check your tank before you buy. Our sourced minimum is 29 US gallons.
Swordtail tank mates and swim zone
Top
Spends most of its time in this part of the tank.
Trigonostigma heteromorpha
Danio rerio
Puntius titteya
Barbodes semifasciolatus
Mikrogeophagus altispinosus
Corydoras aeneus
Betta splendens
Betta often does best alone. Only try this in a larger, planted tank, and watch closely.
Corydoras paleatus
Their pH ranges barely overlap, so you will have little room for error.
Corydoras panda
Their pH ranges barely overlap, so you will have little room for error.
Ancistrus cirrhosus
Their pH ranges barely overlap, so you will have little room for error.
Paracheirodon innesi
Swordtail is big enough to eat or bully a fish as small as Neon Tetra.
Paracheirodon axelrodi
Swordtail is big enough to eat or bully a fish as small as Cardinal Tetra.
Hyphessobrycon amandae
Swordtail is big enough to eat or bully a fish as small as Ember Tetra.
Hyphessobrycon herbertaxelrodi
Swordtail is big enough to eat or bully a fish as small as Black Neon Tetra.
Hemigrammus erythrozonus
Swordtail is big enough to eat or bully a fish as small as Glowlight Tetra.
Swordtail feeding and care
How to feed
- Feed flakes or pellets with a good share of vegetable content.
- Add frozen or live foods, which suit this generalized omnivore.
- Feed small portions you can see finished within a couple of minutes, because overfeeding fouls the water fast.
Telling males from females
Adult males have the long sword on the tail and a pointed anal fin. Females are larger and rounder, with no sword.
Plants that suit it
Species facts
- Family
- Poeciliidae
- Native to
- Mexico to Honduras
- Adult size
- 5.5 in (14 cm)
- Temperament
- Semi-Aggressive
- Social needs
- Harem/Pairs
- Diet
- Omnivore
- Water flow
- Moderate
- Substrate
- Any
- Live plants
- Yes - Loves Plants
- Shrimp
- Will Eat Shrimp
- Fin nipping
- Low
- Vulnerable to nippers
- No
- Breeding
- Easy Livebearer
Swordtail FAQ
What size tank do Swordtails need?
Our sourced minimum is 29 US gallons (108 liters), with a footprint of 120 x 30 cm. A bigger tank is always easier to keep stable.
How many Swordtails should I keep?
Keep at least 3 fish. Bigger groups usually look better and behave more confidently.
What can live with Swordtails?
Good matches on our list include Harlequin Rasbora, Zebra Danio and Cherry Barb. Avoid Neon Tetra and Cardinal Tetra.
How long do Swordtails live?
Care guides report about 3–5 years. Stable water and a good diet make the biggest difference.
Can two male swordtails live together?
It depends on the tank. In tight spaces, males spend much of their time squabbling, so a single male with several females is usually simpler.
Where to buy Swordtail
We have not found a store that sells Swordtail under its scientific name yet. We add stores as we confirm them.
Live animals and plants travel by courier. Check the store's live-arrival guarantee, and only buy once your tank has cycled (see how to cycle a fish tank).
Some US states restrict certain species. Check our US state aquarium rules table and your state's own rules before you buy.
Complete the tank
A forgiving setup with room for a small community.
Tank size for this species
At least 29 US gallons (108 L), 120 x 30 cm footprint
Filter
Hang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
We are still choosing products for this.
Heater
Adjustable heater, about 5 W per gallon: 100 W at 20 gallons, about 150 W at 29
Enough power to hold a stable temperature in most homes. Size up for a cold room.
We are still choosing products for this.
Water Conditioner
Dechlorinator such as Seachem Prime
Tap water contains chlorine or chloramine that harms fish.
Seachem Prime US
Fritz Complete Water Conditioner US
API Betta Water Conditioner US
sera aquatan Spain
Tetra AquaSafe Spain
Maker's page · Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test Kit
Liquid kit such as API Freshwater Master
Tracks ammonia, nitrite, nitrate and pH while the tank cycles.
API Freshwater Master Test Kit US
API General & Carbonate Hardness Test Kit US
Maker's page · Sold at The Shrimp Farm · Sold at Bulk Reef Supply
sera aqua-test box (Cl) Spain
JBL PROAQUATEST COMBISET Plus NH4 Spain
Why we chose these (Best Test Kit for a Freshwater Aquarium). Nobody here has used or tested them.
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.