Swordtail Tank Mates: Complete Compatibility Guide
Xiphophorus helleri · 40 compatible species on file
Finding the Right Tank Mates for Swordtail
Choosing the right swordtail tank mates comes down to three things: water parameter overlap, temperament match, and adult size gap. Swordtail (Xiphophorus helleri) is a semi-aggressive species native to Central America that reaches 5.0 inches in adulthood and needs a 20-gallon minimum tank kept at 72–78°F with a pH between 7.0 and 8.0. Any fish you're considering as a swordtail compatible fish must thrive in those same conditions — chronic water stress from a mismatched temperature or pH range is the number-one cause of disease, faded color, and shortened lifespan in community tanks. That is why every pairing on this page is scored against Swordtail's specific water envelope rather than a generic "community fish" label.
Swordtail is semi-aggressive, meaning it can coexist with many community fish but may become territorial — especially during feeding or breeding. The best swordtail tank mates are peaceful species large enough not to be bullied, or other semi-aggressive species of comparable size housed in a tank big enough to give each fish its own territory. Avoid long-finned or slow-moving species that may draw nipping, and provide visual barriers (driftwood, dense plants) to break sight lines. Below you'll find every swordtail compatible fish in the AquaMateCheck database, scored on water overlap, temperament, and predation risk — each linking to a detailed pairwise compatibility page.
Tank Setup for a Swordtail Community Aquarium
A successful Swordtail community tank starts with size and ends with maintenance. Use a tank at least as large as the most demanding species in the group (20 gallons minimum for Swordtail alone, and larger once you add companions). Maintain the temperature inside 72–78°F and the pH inside 7.0–8.0 with a reliable heater and weekly testing. Add hiding spots — caves, driftwood, and live plants like Java fern or Amazon sword — so every fish can claim a retreat. Perform 25% water changes weekly to keep ammonia and nitrite at zero and nitrate below 20 ppm, since two or more species multiply the bioload. Always quarantine new arrivals for 2–4 weeks before introducing them to the display tank to prevent disease outbreaks.
Swordtail Quick Specs
| Adult Size: | 5.0" |
| Temperament: | semi-aggressive |
| Min Tank Size: | 20 gallons |
| Temperature: | 72-78°F |
| pH Range: | 7.0-8.0 |
| Diet: | omnivore |
| Origin: | Central America |
🟢 Highly Compatible Tank Mates (8)
These species share strong water-parameter overlap with Swordtail and a low-conflict temperament match — the safest swordtail tank mates.
🟡 Compatible with Caution (32)
These pairings can work but need a larger tank, careful group sizing, or close monitoring during the first week.
🔴 Species to Avoid (29)
These pairings scored RISKY due to water mismatch, aggression, or predation. They are not recommended swordtail tank mates.
Frequently Asked Questions
What fish can live with Swordtail?
8 species are highly compatible (GOOD verdict) with Swordtail, including Bristlenose Pleco, Bristlenose Pleco, Electric Blue Acara and more. An additional 32 species can coexist with careful management. Always confirm water parameter overlap on the full compatibility page before adding new tank mates.
How many Swordtail can I keep in one tank?
Swordtail requires a minimum tank size of 20 gallons, kept at 72-78°F with a pH between 7.0 and 8.0. Size your aquarium for the most demanding species in the community and maintain pristine water quality with weekly 25% water changes.
What should I avoid keeping with Swordtail?
Avoid any species with no temperature or pH overlap, aggressive fish that may bully a 5.0-inch semi-aggressive species, and fish large enough to swallow Swordtail. Always quarantine new arrivals for 2–4 weeks and verify the compatibility verdict on the pairing page before introducing new fish.
Tools & Resources
Accuracy note: Compatibility scores use expert rules + FishBase.org data. Individual fish behavior varies — a semi-aggressive Swordtail may act differently from its species average. Always observe new introductions for the first 48 hours and quarantine all new arrivals for 2–4 weeks.