Forktail rainbowfish vs Slim betta: can they live together?

Verdict: With caution

  • The Slim betta can be semi-aggressive or nip fins.
  • The Slim betta grows about twice as long as the Forktail rainbowfish; watch for bullying or predation.
  • Both are comfortable at 24–26°C (75–79°F).
  • A pH of 6.5–7.5 suits both.
  • Minimum tank for the pair: 75 L (20 US gal)

Side by side

Forktail rainbowfishSlim betta
Adult size5 cm (2 in)10 cm (3.9 in)
Minimum tank75 L (20 US gal)75 L (20 US gal)
Temperature24–26°C (75–79°F)24–30°C (75–86°F)
pH6.0–8.06.5–7.5
Hardness5–12 dGH (89–214 ppm)5–15 dGH (89–268 ppm)
TemperamentPeacefulSemi-aggressive
Community tankGoodGood
Care levelEasyEasy
DietOmnivoreOmnivore

Species profiles