Swordtail: Tank Size, Tank Mates and Setup
An active livebearer; males carry a long sword on the tail. Needs swimming room, so 29 gallons or larger.
- Minimum tank
- 29 gallons
- Temperature
- 72–79°F
- Group size
- 3 or more
- Adult size
- 5 inMiddle of the tank
- A strong jumper, so use a tight lid.
- Males can bully each other; keep one male or several.
Xiphophorus hellerii. Figures are commonly published care ranges; see how it works.
How many swordtails per tank size
The most you could keep if swordtails were the only species. Open a size in the builder to add tank mates.
| Tank | Swordtail, kept alone | |
|---|---|---|
| 5 gallon | Too small (needs 29+ gal) | |
| 10 gallon | Too small (needs 29+ gal) | |
| 20 gallon | Too small (needs 29+ gal) | |
| 29 gallon | Up to 6 | Plan this tank |
| 40 gallon | Up to 9 | Plan this tank |
| 55 gallon | Up to 12 | Plan this tank |
| 75 gallon | Up to 16 | Plan this tank |
What you need for swordtails in a 29-gallon tank
A starting setup: 3 swordtails in the smallest standard tank that suits them.
29-gallon tank
- These fit a 29-gallon tank and get along. Aim for about 76°F.
- Swordtails breed readily. Keep males only if you don't want fry.
Equipment, sized for this tank
Starter supplies
Paid links. As an Amazon Associate, TankStarter earns from qualifying purchases. Sizes are estimates from published care guidelines, not hands-on testing.
Swordtail tank mates
These share a temperature range and temperament with swordtails, with no warnings from our checks.
Use caution with: fancy goldfish, cherry shrimp, amano shrimp. Add them in the builder to see why.
Plan a tank around swordtails
Add tank mates, check the stocking level and get the equipment sized for your tank.
Open the tank builderSwordtail questions
What size tank does a swordtail need?
At least 29 gallons for a group of 3. A larger tank is more stable and gives you more choice of tank mates.
How many swordtails can I keep in a 29-gallon tank?
Up to about 6 if they are the only species in the tank. Fewer if you add other fish.
Do swordtails need a heater?
Usually yes. Swordtail does best at 72–79°F, which is warmer than most rooms. A 29-gallon tank needs about 100 watts in a 68°F room.
What fish can live with swordtails?
Good matches include bettas, neon tetras, cardinal tetras, ember tetras, rummy-nose tetras, black skirt tetras. They share a temperature range and temperament with swordtails.