Swordtail Fish Care Guide: Tank, Diet, Breeding & Tank Mates

Swordtails (Xiphophorus hellerii) are colorful, active freshwater fish known for their striking tails, friendly nature, and beginner-friendly care needs. These livebearers are easy to keep, breed readily, and add lively movement to community tanks. In this guide, you’ll learn how to care for Swordtail fish, from setting up their tank to choosing the right food, tank mates, and breeding tips.

Table of Contents

Swordtail Fish Care Chart

Aspect	Recommended Range / Setup
Tank Size	20 gallons minimum (longer tank preferred)
Water Temperature	72–82°F (ideal: 75–78°F)
pH Level	7.0–8.3
Water Hardness	12–30 dGH
Substrate	Gravel or sand
Plants	Java fern, Vallisneria, Hornwort (with open swimming space)
Filtration	Sponge or hang-on-back filter with moderate flow
Lighting	Moderate lighting to enhance color
Feeding Frequency	1–2 times daily + vegetables 2–3 times weekly
Tank Mates	Platy fish, guppies, mollies, corydoras, rasboras, snails
Water Changes	20–30% weekly

Ideal Tank Setup for Swordtails

Tank Size

Swordtails are active swimmers. A 20-gallon tank is the minimum, but bigger is better, especially if keeping multiple males. Choose a long tank over a tall one to give them space to swim.

Substrate & Plants

Use gravel or sand substrate. Add live plants like Java fern, Vallisneria, or Hornwort to provide shelter and reduce stress. Keep open swimming space at the front.

Filtration & Lighting

Use a sponge filter or hang-on-back filter with gentle to moderate flow.
Moderate lighting helps showcase their colors.
Always use a lid or cover—Swordtails are known jumpers!

Water Parameters & Maintenance

Swordtails are hardy, but clean, stable water helps them thrive:

Temperature: 75–78°F (use a heater if needed)
pH: 7.0–8.3
Hardness: 12–30 dGH
Water change: 20–30% weekly

Regular maintenance prevents ammonia spikes and keeps fish healthy.

Swordtail Fish Diet

Swordtails are omnivores. A varied diet supports their color and health.

What to Feed

Staple: High-quality flakes or micro pellets
Veggies: Blanched zucchini, cucumber, spinach
Protein treats: Daphnia, brine shrimp, bloodworms (frozen or live)

Feeding Schedule

Feed 1–2 times daily. Only provide what they’ll finish in 1–2 minutes. Supplement veggies 2–3 times a week.

Swordtail Behavior & Tank Mates

Swordtails are peaceful but males can be territorial in small spaces.

Tips for Harmony

Keep 1 male for every 2–3 females
Avoid too many males without lots of space
They’re happiest in small groups and swim in the middle or top levels

Best Tank Mates Swordtail

Tank Mates to Avoid

Bettas
Tiger barbs
Small-tank angelfish
Known fin-nippers

Breeding Swordtails

Swordtails are prolific livebearers.

Breeding Basics

Gestation: ~28–30 days
Females can store sperm and produce several batches of fry
Males constantly court females

Protecting Fry

Add dense plants or use breeding boxes
Move fry to a separate grow-out tank
Feed them crushed flakes or baby brine shrimp

Plan ahead, as swordtail fry numbers can grow fast!

Common Health Issues & Prevention

Swordtails are tough, but common issues include:

Ich (white spots)
Fin rot
Ammonia poisoning
Stress from overcrowding or overbreeding

How to prevent problems:

Do regular water changes
Avoid overcrowding
Balance the male-to-female ratio
Feed a varied, clean diet

Frequently Asked Questions

Do Swordtails need a heater?
Yes. They thrive at 72–82°F.

Are Swordtails beginner-friendly?
Absolutely. They’re hardy and easy to breed.

Can Swordtails live alone?
Yes, but they prefer small groups.

Will Swordtails eat their fry?
Yes. Use plants or a breeder box to protect babies.

How many Swordtails can live in a 20-gallon tank?
3–5 Swordtails is ideal, keeping more females than males.