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 or more
- Lifespan
- 3–5 years
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.
Swordtail care mistakes to avoid
- 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 setup
A forgiving setup with room for a small community.
TankAt least 29 US gal (108 L), 120 x 30 cm
The smallest tank our sources give for Swordtail. We list only tanks that hold this volume (allowing 10%, so a standard size counts) and have at least this much floor.
Picks for Spain are still being checked. The options below are for the US, and we have not confirmed that they are sold in Spain.
Aqueon Standard Glass Aquarium 55 Gallon US
Why we chose these (Best 20-Gallon Fish Tank: 20 Long or 29?). Nobody here has used or tested them.
Starter kitA kit with the tank, filter and light in one box
We list only kits whose tank fits Swordtail, up to twice its minimum volume. A kit whose heater has a fixed setting shows only when that setting is inside Swordtail's temperature range.
None of our picks for Spain suits this species. The options below are for the US, and we have not confirmed that they are sold in Spain.
Tetra Complete LED Aquarium Kit 55 Gallon US
Check the heater's setting
Why we chose these (Best Aquarium Starter Kit: What to Look For). Nobody here has used or tested them.
FilterHang-on-back or large sponge filter
Easy to maintain and strong enough for a community without blasting the fish.
Seachem Tidal 55 Power Filter US
Marineland Penguin PRO 175 Power Filter US
Eheim LiBERTY 130 Hang-on Filter Spain
Seachem Tidal 35 Power Filter Spain
Why we chose these (Best Filter for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
HeaterKeep it at 61–82 °F (16–28 °C)
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.
Aqueon Pro Adjustable Heater 100 W US
Aqueon Submersible Glass Heater 100 W US
Eheim Thermocontrol e 100 Heater Spain
Tetra HT 100 Electronic Heater Spain
Why we chose these (Best Heater for a 20 to 29-Gallon Tank). Nobody here has used or tested them.
Water conditionerDechlorinator 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
Sold at Kiwoko · Sold at Tiendanimal · Sold at zooplus.es · Maker's details
Why we chose these (Best Water Conditioner for Betta Fish). Nobody here has used or tested them.
Test kitLiquid 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
See it at The Shrimp Farm (a retailer; affiliate link) · Sold at Bulk Reef Supply · Maker's details
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.
SubstrateDecor is not critical; wild forms also suit a stream with water-worn rocks.
We are still choosing products for this.
Hiding places and decorFloating plants and driftwood are appreciated; rocks suit a stream-style tank.
We are still choosing products for this.
PlantsSafe with live plants
Cycle the tank before adding animals. See our guide on how to cycle a fish tank.
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.
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.
Swordtail facts and sources
- 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
Sources
- Seriously Fish: Tank size, water ranges and behavior
- FishBase: Cross-check of water ranges and size
Lifespans are approximate and come from aquarium care guides, because these databases rarely publish them.
Where sources differ, we show the Seriously Fish aquarium figures.
Spotted something wrong? Report a parameter correction. For a sick fish, see our veterinary disclaimer.