HomeCompare fishDwarf rainbowfish vs Crescent betta Dwarf rainbowfish vs Crescent betta: can they live together? Verdict: CompatibleBoth are comfortable at 24–28°C (75–82°F).A pH of 6.5–7.0 suits both.Minimum tank for the pair: 150 L (40 US gal)Side by sideDwarf rainbowfishCrescent bettaAdult size5 cm (2 in)6 cm (2.4 in)Minimum tank150 L (40 US gal)40 L (11 US gal)Temperature22–28°C (72–82°F)24–30°C (75–86°F)pH6.5–7.56.0–7.0Hardness8–18 dGH (143–321 ppm)5–19 dGH (89–339 ppm)TemperamentPeacefulPeacefulCommunity tankGoodGoodCare levelEasyEasyDietOmnivoreOmnivoreSpecies profilesDwarf rainbowfishMelanotaenia praecoxCrescent bettaBetta imbellis