HomeCompare fishRed rainbowfish vs Blackfin pearlfish Red rainbowfish vs Blackfin pearlfish: can they live together? Verdict: Not recommendedThe Blackfin pearlfish is best kept in a species tank.The Blackfin pearlfish is aggressive towards other fish.Both are comfortable at 22–24°C (72–75°F).A pH of 7.0 suits both.Side by sideRed rainbowfishBlackfin pearlfishAdult size12 cm (4.7 in)7 cm (2.8 in)Minimum tank150 L (40 US gal)55 L (15 US gal)Temperature22–25°C (72–77°F)18–24°C (64–75°F)pH7.0–8.06.0–7.0Hardness9–19 dGH (161–339 ppm)5–12 dGH (89–214 ppm)TemperamentPeacefulAggressiveCommunity tankGoodNot suitableCare levelEasyModerateDietOmnivoreCarnivoreSpecies profilesRed rainbowfishGlossolepis incisusBlackfin pearlfishAustrolebias nigripinnis