HomeCompare fishMountain rainbowfish vs Dwarf rainbowfish Mountain rainbowfish vs Dwarf rainbowfish: can they live together? Verdict: With cautionThe Mountain rainbowfish grows about twice as long as the Dwarf rainbowfish; watch for bullying or predation.Their temperature ranges only just meet, at 22°C (72°F).A pH of 6.5–7.2 suits both.Minimum tank for the pair: 210 L (55 US gal)Side by sideMountain rainbowfishDwarf rainbowfishAdult size10 cm (3.9 in)5 cm (2 in)Minimum tank210 L (55 US gal)150 L (40 US gal)Temperature18–22°C (64–72°F)22–28°C (72–82°F)pH6.5–7.26.5–7.5Hardness–8–18 dGH (143–321 ppm)TemperamentPeacefulPeacefulCommunity tankWith cautionGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesMountain rainbowfishMelanotaenia monticolaDwarf rainbowfishMelanotaenia praecox