Swordtail fish care for beginners

Care guide · About 5 minutes to read · By Andy · Updated Oct 26, 2026

Swordtails are hardy, active livebearers named for the long "sword" on the male's tail. They're easy to keep and come in red, orange, green, black and pineapple colors. They just need more room than their size suggests, and a lid.

Swordtail facts

Size: 4 to 5 inches, not counting the sword
Tank: 30 gallons or more, and a 40 breeder or 55 is better
Temperature: 72–79°F
Water: hard water with a pH of about 7 to 8
Group: 3 or more, with one male to two or three females
Lifespan: about 3 to 5 years

Setting up the tank

Length matters. Swordtails are fast swimmers, so a long tank beats a tall one.
Use a lid. Swordtails are well known for jumping out.
Plants and open space. Plants give females a break from males, and open water gives everyone room to swim. See easy live plants.
Hard water. If your water is soft, crushed coral in the filter raises hardness gently.

Males, females and babies

Males have the sword on the lower tail and a pointed fin under the belly. Females have a plain fan tail and a rounder body.
Only one male in tanks under about 55 gallons. Males spar, and the top male may bully the others.
Babies come about every month if males and females are together. Dense plants let some survive. See guppy care for raising livebearer fry.

Feeding

Feed a quality flake or small pellet once or twice a day, with some vegetable-based food and frozen or freeze-dried treats a few times a week. See how often to feed fish.

Tankmates

Good: platies, mollies, corydoras, bristlenose plecos, danios and larger peaceful tetras.
Avoid: very small fish and shrimp, which adults may eat, fin nippers, and fish that need soft, acidic water.

1. Swordtail trio

3 swordtails (1 male, 2 females) · 6 bronze corydoras

Keep at 72–78°F · 71% stocked in the calculator
Open this plan in the calculator

An easy first swordtail tank. Swordtails swim fast and need length.

2. Swordtails and platies

3 swordtails · 6 platies · 1 bristlenose pleco

Keep at 72–79°F · 65% stocked in the calculator
Open this plan in the calculator

Swordtails and platies are close cousins that like the same hard water. They can crossbreed, so expect mixed babies.

3. Big livebearer tank

4 swordtails · 4 mollies · 6 platies

Keep at 72–79°F · 67% stocked in the calculator
Open this plan in the calculator

Colorful and lively. Keep more females than males of each kind.

Swordtail tank picks

Paid links: if you buy through these Amazon links, I earn a small commission at no extra cost to you.

Planning your first tank? Your First Aquarium covers setup, cycling and stocking step by step, with care cards for 15 beginner fish. Get the guide for $12

Want to breed swordtails? The Fish Breeding Planner ($9) has a step-by-step page for them, a fry food guide and printable spawn and fry logs. How to breed swordtails is free here too.