HomeCompare fishMountain rainbowfish vs Forktail rainbowfish Mountain rainbowfish vs Forktail rainbowfish: can they live together? Verdict: Not recommendedThe Mountain rainbowfish grows about twice as long as the Forktail rainbowfish; watch for bullying or predation.Their temperature ranges don't overlap.A pH of 6.5–7.2 suits both.Side by sideMountain rainbowfishForktail rainbowfishAdult size10 cm (3.9 in)5 cm (2 in)Minimum tank210 L (55 US gal)75 L (20 US gal)Temperature18–22°C (64–72°F)24–26°C (75–79°F)pH6.5–7.26.0–8.0Hardness–5–12 dGH (89–214 ppm)TemperamentPeacefulPeacefulCommunity tankWith cautionGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesMountain rainbowfishMelanotaenia monticolaForktail rainbowfishPseudomugil furcatus