Did you know that Koi Swordtails can live up to five years in a well-maintained aquarium? These striking fish, known scientifically as *Xiphophorus hellerii*, typically grow to about 10–15 centimeters (4–6 inches) in length and thrive in tanks with a capacity of at least 75.7 liters (20 gallons). They prefer water temperatures between 20–26°C (68–79°F) and a pH range of 7.0 to 8.0. Not only visually appealing but also adaptable, these traits make them suitable for various tank environments. Understanding their characteristics and care requirements is essential for anyone considering adding them to their aquatic collection. Let’s explore what truly makes Koi Swordtails a fascinating choice for aquarists. They require a minimum tank size of 10 gallons (38 liters) and thrive in groups of at least five. Their vibrant colors and peaceful temperament make them popular choices for community tanks among novice aquarists.